Deep Thinkers

Two summers ago, thousands of animal lovers around the world zeroed in on the Office of Naval Operations at the Pentagon with a barrage of letters that rocked the Navy down to its bilges. The source of the public ire was a widely circulated newspaper report that the Navy was recruiting porpoises--those ever-smiling, lovable cousins of the whale--as seagoing kamikaze pilots: living, swimming bombs trained to attack enemy submarines and blow themselves to pieces in the process.

According to the report, Navy researchers at the U. S. Naval Missile Center in Point Mugu, California, had discovered that porpoises, with their uncanny sonar capability, could distinguish between different metals, such as aluminum and bronze. The report suggested that the Navy planned to put this ability to military use by first equipping all friendly submarines with a metal identification tag, composed of some secret-formula metal the porpoises could easily recognize, and then training a battalion of suicidal porpoises, each carrying a large explosive charge, to hunt enemy subs in the open ocean. Presumably, when a porpoise spotted a sub not equipped with the secret-metal I. D. tag, it would attack, detonating the explosive and blowing the sub and itself to smithereens.

Newspaper readers around the world were horrified. This time, the Navy had gone too far. Had it recruited sharks or barracuda or even killer whales for its ghoulish scheme, there would have been barely a ripple. But the beloved porpoise? Our Flipper? Porpoise lovers of the world united and the Navy had a full-blown public-relations typhoon on its hands.

Actually, the whole affair was a big mistake--a small indiscretion that the Navy bumbled into a cause célèbre. While it is true that porpoises can spot the difference between dissimilar metals, it is not true--or it is at least highly unlikely, according to the Navy scientists--that the Navy ever seriously considered the kamikaze scheme. The idea is simply not practical, if possible at all.

The problem arose originally because the purely biological research at the Point Mugu station is, by law, not subject to secret classification. On the other hand, the military objectives of the research may be, and are, secret. Thus, when a reporter who had seen the biological work innocently asked what the Navy intended to do with the information, a flippant escort told him, "Use your own imagination." He did.

Then the Navy compounded its error. Instead of issuing an official and scientifically justifiable denial, the Pentagon abruptly banned any further visits by outsiders to the base and, in fact, canceled all previously scheduled appointments. As a result, the true story never got out. For all anyone knows, the Navy brass is still getting indignant letters.

While the kamikaze scheme was a hoax, the idea of porpoises doing important, useful work for man is certainly not. In fact, these animals unquestionably will play a major role in many of our future activities. According to one scientist in the thick of the research at Point Mugu, "The direct and extensive involvement between porpoise and man in the performance of useful work is a certain and significant development of the very near future."

This prediction, he explains, is dictated--if for no other reason--by our rapidly growing exploration of the sea. Already, we see underwater oil and gas drilling, experimental undersea communities and proposed undersea mining and agricultural projects, and there is talk of many more marine ventures. Many scientists think the sea offers at least as great a challenge--and greater potential rewards--than the exploration of outer space.

The marine environment, of course, is alien to land animals--as hostile as outer space, if not more so. Biologically, human beings will never comfortably adapt to the ocean depths. The porpoise, on the other hand, is perfectly adapted, at least to depths of close to 1000 feet. And it alone among marine creatures offers man a unique combination of adaptation to environment, full cooperation and sufficient brain power with which to master the variety of techniques that will be needed in the conquest of the sea. Thus, barring unforeseen obstacles, the close cooperation between man and porpoise in work in the sea is an almost inescapable certainty.

The first tentative attempt at such cooperation occurred in September 1965, in Operation Sealab II. In this experiment, a group of divers took 15-day turns living and working under 210 feet of water off La Jolla, California. A porpoise named Tuffy carried messages and tools between the divers and the surface. On one occasion, he took a lifeline to a diver who pretended he was lost in the murky water.

Commenting on the experiment, one Sealab scientist expressed disappointment in the very small role Tuffy was allowed to play. Sealab, he said, demonstrated that the potential existed but did not begin to utilize the full talents Tuffy had to offer.

Precisely what those talents are--and to what degree man will be able to use them--will depend to a large extent on what the research now in progress reveals. It is known, for example, that porpoises boast an excellent sonar, or echolocation system, far more complex and generally much better than any machine human engineers have yet devised. It is also believed that the porpoise possesses a high order of intelligence--a rather inexact term that accurately expresses in its inexactitude just about what man knows about porpoise intelligence. Is the porpoise really intelligent in human terms? Or is it simply good at being a porpoise? How much training will the animal take and how complex a task may it be assigned? Will it have to restrict its activities to simple conditioned-response performance, or will it actually understand what it is asked to do and why? Scientists in many different fields are attacking these questions now and much depends on what they discover.

Finally, beyond these questions, there is a further complication. If one grants a high intelligence in the porpoise and a means of matching the porpoise's abilities to the task, will the trainer be able to communicate his needs to the porpoise? Apparently, porpoises have some kind of verbal communication system of their own. Will humans have to learn "porpoiseese" or will porpoises be able to learn English? Research aimed at answering both questions is going on right now.

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To understand the various possibilities and the problems associated with this vital project, a little background is in order.

The porpoise is a member of the whale family, Cetacea, and the term "porpoise" generally refers to some 50 different species spread across all of the oceans of the earth and many of its rivers. The porpoise is not a fish; it is an air-breathing mammal that bears its young alive. It is a highly social animal living in a complex, structured society. It exhibits a wide variety of emotions, apparently communicates with others of its own kind and represents an advanced evolutionary form. In its own way, the porpoise is conceivably as advanced as Homo sapiens himself, in the view of some researchers.

Though all animals can trace their ancestry back to the sea, cetaceans at one time lived on dry land. Judging from their stomach structure, they probably had a common ancestry with the cow, although cetaceans do not chew a cud. Very early in the history of mammals, about 80,000,000 years ago, during the Paleocene epoch, they are believed to have returned to the sea. The first forms to show signs of beginning the long adaptation to the water environment appeared in the Eocene epoch that followed.

It was a difficult adaptation. When a land animal is put into water, all of its systems are thrown out of kilter. The eye becomes virtually useless; the same for the nose. The land ear is adjusted to sound waves one fifth as long as those in water. (Sound travels five times faster in water, so the ear needs to adjust drastically.) A new breathing system must be developed. Feeding becomes a tricky proposition. The animal can better use flippers than the legs, paws, hooves or whatever it had on land.

Why the cetaceans went back to the sea nobody knows, but it makes good sense. This planet is four fifths covered by water and one fifth by land. The sea contains 10 to 100 times as much animal and plant life per area as does the land. In water, gravity ceases to be a problem.

Whatever the reason, porpoises made the long, slow adaptation and today they are beautifully equipped for their life in the sea. They have few natural enemies except for their big cousin, the killer whale--and, of course, man. They have speed, maneuverability and intelligence that allows them to cope with other marine creatures and easily provides them with the necessities of life.

In fact, life for porpoises is rather pleasant. They generally hunt in large groups, rounding up a school of fish like Indians attacking a wagon train and then taking turns entering the circle to feed. They spend a great deal of their time just playing--and breeding. Their society apparently is sexually enlightened, since the females are not at all shy about expressing their needs. One of the first "words" in the porpoise communication system that scientists were able to identify was something translated as a come-hither call.

A group of porpoises in a tank will spend nearly 24 hours a day enjoying sex. At oceanariums, it's quite common for two porpoises to have intercourse during a pool show, and oceanarium keepers are continually surprised that visitors--including Mom, Dad, Sis and Bud--don't seem to mind a bit. Even so, in most oceanariums there are usually a few porpoises hidden in tanks the audience can't see. These animals are just too randy for (continued on page 150)Deep Thinkers(continued from page 102) popular viewing. When there are no female porpoises around, males will rub their penises on anything they can find: other males, pipes, pool walls, even human divers in their pool. Females masturbate with equal exuberance. If a female is in need--which is almost constantly--she will first issue a come-hither call. If that doesn't work, she will swim to a male and stroke his cloacal slit area until he gets an erection--which, by the way. is very apparent. If the male is simply too tired and if there are no other males available, she will find a similarly inclined female and the two will take turns masturbating each other with their flippers, or dorsal fins. Far less is known about porpoise sex life in the open ocean, but in oceanarium holding tanks, homosexuality is rampant.

Pregnancies last about a year, usually with several young females assigned to the expectant mother as nurses and mid-wives during the latter part of the pregnancy. The young are born under water, tailfirst to avoid drowning, and the mother pushes them to the surface for their first breath. They can swim almost immediately and begin nursing within an hour or two. Nursing takes only a few seconds, because the mother is able to squirt a large volume of milk into the baby's mouth very quickly. The baby often remains with its mother for up to a year and retreats to her, in time of stress, for up to six years.

Little is known about porpoise health problems in the open ocean, but in captivity, disease takes a heavy toll. Pneumonia is the biggest killer. Porpoises are also susceptible to a disease germ that causes parasyphilis in pigs. Ulcers are a common cause of death in captivity. A physiologist who has studied porpoises explains that in captivity. they are like creatures coming from another planet. In the open ocean, they get no exposure to land-borne disease germs and, hence, have no opportunity to build up a resistance. When they hit land, the local germs often lay them low. In fact, one of the most active areas of research on porpoises today is directed at porpoise pathology. If this animal is to be an important co-worker with humanity, our scientists must learn to keep it alive.

Although the most fruitful phase of our relationship with the porpoise is likely to come in the future, this relationship (perhaps "romance" might be a better word) is very old. going back many thousands of years. Porpoises, or dolphins, abound in mythology. They are sacred to the god Apollo, who, as protector of mariners, is said to frequently assume the form of a dolphin. Apollo's shrine at Delphi, home of the oracle, was named for the dolphin.

In a story related by Herodotus, Arion is saved from the sea by dolphins he charmed with his music after mutinous sailors threw him overboard. The famous "boy on a dolphin" is believed to be Arion. This art figure and other representations of the dolphin have been found on no fewer than 60 different ancient coins. The Greeks also gave the animal one of its names--dolphin--from the Greek word delphis, meaning womb. This was simply a recognition that the animal bears its young alive from a womb.

Another ancient people, the Gauls, gave the animal its other name, which accounts for the modern confusion about what to call it. These early Frenchmen were familiar with a blunt-nosed species and promptly named it porpoise, or "hog fish," from the Latin words porcous, swine, and piscis, fish. Today, the English-speaking world strongly favors the word porpoise for the name of the group, reserving dolphin for particular species--bottle-nosed dolphin, North Atlantic white-sided dolphin, etc. This also avoids any confusion with a true fish that is also called dolphin in English. The majority of scientists today take no position on either name, because both, for scientific purposes. are imprecise. Scientists refer to genera, such as Tursiops, Delphinus or Stenella.

Occasionally, however, one finds a scientist such as Dr. John C. Lilly, now head of the Communications Research Institute in Miami, who seems to care a great deal. When a reporter approached Dr. Lilly at the First International Symposium on Cetacean Research, in the autumn of 1963, and asked about porpoises, the good doctor replied: "I don't know anything about porpoises: I only know about dolphins." Then he turned on his heel and left the room. On the other hand, two West Coast scientists who often coauthor scientific papers generally flip a coin over which term they will use, or sometimes "purposely use 'porpoise'--just to annoy Dr. Lilly." The porpoise familiar to most Americans through oceanarium shows, movies or television is usually a bottle-nosed dolphin, Tursiops truncatus. The first Flipper--besides being a girl--was a Tursiops.

The modern porpoise boom probably began in the late 1940s, when the oceanariums discovered that porpoises make marvelous showmen and are real crowd pleasers. Today, more than a dozen such oceanariums operate in this country--the two Marinelands in Florida and California, the Miami Seaquarium, Sea Life Park in Honolulu, and others. Several more are opening in Europe. They feature porpoises playing water polo and basketball, taking fish from a trainer's hand or mouth, ringing bells, or anything else the porpoises or trainers can think of. (Porpoises often originate many of the tricks themselves. The trainer simply encourages the animal when it does a new and useful trick and in a short time, it becomes a regular part of the show.) The crowds love it.

Probably the first serious scientific research on porpoises began at these oceanariums. Prior to the 1940s, nearly all of the information about the animals came from reports by old sailors, whalers, passengers on ocean liners and other untrained observers. As a result, quite a few misconceptions developed along with the solid scientific data. One of the most popular misconceptions, for example, is that porpoises push drowning sailors to land. It is probably true that such incidents have occurred, but scientists have not been alone in noting that porpoises will play with almost anything they find floating in the sea, including old mattresses. And one hears such stories, of course, only from persons who were pushed toward the land.

Another misconception, which only very recently has been put to rest, is the speed at which porpoises swim. A few years ago, scientists were allowing for speeds of up to 40 or 45 mph--and some reports suggested up to 75 mph. Such speeds seemed to defy all the laws of physics, and hydrodynamics experts were considering various exotic theories to explain them. These theories were finally shot down in 1965 by open-ocean speed trials off Hawaii--in which a test animal hit a top speed of 181/2 mph. It is now accepted that most porpoise species have a top speed of between 17 and 23 mph, with one or two species getting up to about 25 mph.

Other notions about porpoises have been widely exaggerated--notably, claims about the animal's intelligence. The porpoise's "I. Q." still has not been determined, but claims that the animals are as intelligent as man, or even more so, at the very least remain to be proved. These claims tend to obscure some of the more practical discoveries about the porpoise that current research is producing.

One interesting discovery, for example, that could prove a tremendous boon to man, is the process by which the porpoise converts sea water to usable fresh water. Although the research is only in its infancy, it appears that when a porpoise dives, it creates a miniature freshwater rainstorm in its closed blowhole. The Office of Naval Research has devoted extensive funds in the past to learning the workings of the penguin's salt gland (another biological converter of sea water). This new discovery in porpoises could provide Navy scientists with an important clue to the solution of a sailor's age-old problem.

The best example of potential practical benefits from porpoise research is in the area of sonar, which originally brought the Navy into the porpoise field in 1950. Sonar, or, more properly, echolocation, is a method of detecting underwater objects with sound waves. Scientists agree that the best sensory mode by far in water is sound. In sonar, a sound wave is sent out from a ship, is reflected by underwater objects and returns to the ship as an echo. The time it takes for the sound wave to make the round trip gives the distance from the ship to the underwater object. The strength and duration of the echo tell something about the object's size, shape and rigidity. The Navy has been using sonar devices for several decades but still is unable to duplicate the precision of the sonar mechanism the porpoise uses to navigate and to find food.

To fully appreciate the complexity of the porpoise sonar system, one might consider the problems involved in a seemingly simple act many people have witnessed: The scene is an oceanarium and it is feeding time for the porpoises. A trainer stands on a high platform and throws a fish into the air. Suddenly, from beneath the surface, a porpoise explodes into the air, grabs the fish and falls back into the tank. Simple? The Defense Department, and this author, deeply wishes we had a missile-detection system that good.

In Navy jargon, this maneuver involved the following processes: target detection, target identification, target trajectory computation and intercept course computation, all in a fraction of a second. It should be noted that when experimenters tried to fool the porpoises with decoy fish, the porpoises would have none of it. They were able to obtain enough information from the echo--target size, density, shape, surface texture, etc.--to tell the difference between a real fish and a decoy. By contrast, the Navy's present sonar is hard pressed to tell a submarine from a whale.

The complete porpoise sonar system is not yet fully understood, but a number of facts and theories have emerged. Porpoises emit a variety of sounds roughly described as whistles, clicks, yaps, barks, moans, and so on. The frequencies of the sounds vary from as low as 100 cycles per second to about 170,000 cycles per second. (For comparison, humans hear up to about 16,000 cycles per second.) The porpoise uses a click sound in its sonar. If one listened under water, a series of porpoise sonar clicks would sound very much like a creaking door or a Bronx cheer.

Low-frequency sound waves do not carry as much information as higher frequencies but travel farther through water. Thus, it is generally believed that porpoises use low-frequency clicks for long-distance navigation (to avoid large obstacles and spot shore lines) and high-frequency clicks for close inspection of objects. The high-frequency clicks occur in what the Navy would call short-range, high-resolution sonar.

We still don't know exactly how the porpoise hears echoes. It was discovered just recently that porpoises don't hear through their ears at all. But since they have land ears, this is not surprising. It is also fairly well established that the animal does absorb sound waves through its lower jawbone, through its forehead and through two fatty pads in either cheek. But the pathway of the sound waves from these receptors to the brain so far has eluded scientists.

The fatty pads in the cheeks represent a recently discovered natural adaptation. Dr. Kenneth Norris of UCLA has made careful measurements of the angles the cheeks make with sound waves. Just this year, Dr. Norris discovered that when an incoming sound wave hits the cheek at angles of 8 degrees or less, the sound is totally reflected and unheard. But at 8.8 degrees, only eight tenths of a degree difference, the porpoise should hear 63 percent of the sound. Thus, by making very slight sidewise movements of the head, the porpoise can cut off one cheek receptor or the other and obtain a precise location of the source of a sound.

When a porpoise approaches an object such as a fish, it sends out a narrow beam of high-frequency clicks. The click rate is adjusted so that the echo returns in the first half of the interspace between two clicks. As the animal gets closer to the target, the echo comes back faster and faster, getting closer and closer to the original click. The clicks and echoes come so fast that they produce a tone, which rises in pitch as the porpoise closes on the target. It sounds very much like an automobile tire accelerating on a gravel road--at first clicking and then blending into a rising hum. The change of pitch tells the porpoise his distance to the target and his rate of approach.

The echo itself consists of two distinct sounds. The first is called a "rigid body signal," reflected by the surface of the target. This part of the echo gives the porpoise the distance to the target and its size. The smaller an object is, the more sound will go around it--and the weaker the echo. Thus, the strength of the echo gives the porpoise the size of the target.

The second sound is an internal echo. The wave enters the target and reverberates inside it, as in a bell. The resulting sound has a varying pitch, rather like a short melody. Different materials play different melodies. Depending upon how hard and brittle the object is, the internal echo will be louder or softer. Thus, from the internal echo, the porpoise obtains an excellent idea of the target's interior structure, the nature of the material and its degree of hardness. It was this ability to reverberate targets, such as pieces of metal, and speculation about its application to enemy submarines, that led to the kamikaze fabrication that so embarrassed the Navy.

Just how precise is this system? Dr. W. H. Dudok van Heel of the Netherlands relates the following demonstration: "When starting to feed a common porpoise, which was not particularly hungry, with fish dead at least one and a half days, I observed several times that the porpoise took the first fish but let it go after tasting it. When the second fish offered was a completely fresh one, it was swallowed after a careful approach. When the third one was again not fresh, the porpoise turned away, sometimes more than half a meter from the fish." A sonar system that can tell the freshness of fish under water must be considered quite remarkable.

In another experiment, Drs. Norris and Ronald Turner asked a porpoise named Alice to distinguish between two steel balls of various diameters. Alice was blindfolded to be sure she used only her sonar. When the difference in size was more than a quarter of an inch, Alice picked out the larger ball nearly every time, and she was able to compile a high percentage of correct answers even when there was only a quarter-inch difference. Just to make sure she wasn't guessing or cheating, the scientists sometimes offered her two identical balls. According to Dr. Norris, she knew she was being kidded and quit.

Actually, he explained, she asked herself two questions: Are the two balls different? And, if so, which is larger? When she got an identical echo from both balls, this was a "no" answer to her first question and she immediately knew someone was pulling her flipper.

One might ask why the Navy cannot duplicate this system in its own sonar. For one thing, despite the foregoing, the porpoise sonar system is still not fully understood. Secondly, a computer to duplicate the mental processes a porpoise is believed to perform with its echo data would probably fill several rooms. As a cheering note to those who are depressed or awed by the computer age, machines are still far from duplicating that engineering marvel called the natural brain.

The natural brain of the porpoise, in fact, has excited as much scientific interest as the porpoise sonar. The brain is about 40 percent larger than a human brain, appears to be twice as convoluted (generally considered a sign of intelligence) and, according to a Johns Hopkins study, has more neurons, or nerve cells, per cubic centimeter. All of this leads to the interesting speculation that porpoises may be more intelligent than man. This view is seriously entertained by a portion of the scientific community, although not a majority. An equivalent group of scientists feels the porpoise probably ranks in intelligence with the dog or the chimpanzee but not as high as man. But most scientists agree that not enough information is available to make a precise determination and that, even if it were, such a determination would be exceedingly difficult--if not impossible.

There is evidence, however, on both sides of the question. Certainly, the highly complex social organization of the porpoise schools is an indication of intelligence. The cooperative hunting tactics require a measure of intelligence. The ease with which porpoises have handled most training tasks in captivity further suggests a high intelligence. But one of the basic problems is how to measure intelligence. Is an intelligence test in human terms a fair measure of the intelligence of another species?

Simple behavioral observations have been contradictory. If a baby is born dead, for example, a porpoise mother may keep it with her, balancing it on her head for many weeks, until it literally rots away. Is this intelligence or stupidity? The Japanese frequently hunt porpoises for food and oil. They have no difficulty rounding them up simply by slapping the water and then herding them into an enclosure to be killed. Is this intelligence or stupidity?

Dr. Norris offers a possible explanation: The porpoise, he says, is necessarily an "acoustic animal." For all intents and purposes, it is deprived in water of the senses of sight, taste, smell and touch--except at extremely close distances. To learn about its environment, it must depend almost solely on its internal sense of equilibrium, plus its hearing, which provides information through its sonar system and through communication with others of its kind. Even in the area of communication, it is largely dependent on sound. Other creatures communicate in their fashion: A dog barks, bristles, wags its tail, shows its teeth. Human beings speak, write, gesticulate, make facial expressions, act out thoughts. Other animals can and do exchange information through sight, sound, smell and touch. But the porpoise is imprisoned in its streamlined, torpedolike body with a single smile frozen on its face. It must depend solely on sound.

It is possible, Dr. Norris says, that the huge brain of the porpoise is devoted in large part to the processing of acoustic data. And it is also possible that the portion of the brain left free to handle other mental functions may, in fact, be relatively small.

Until such a theory is proved, however, research will go on in the hope of discovering some key to porpoise intelligence. Scientists in the field say that such a key will most likely be found in the area of porpoise communication. There is evidence that they do talk to one another in a kind of whistle language. A number of years ago, Dr. John Dreher and Will Evans at the Lockheed-California Company were studying this language by making simultaneous recordings of porpoise sounds and underwater motion pictures of porpoise actions. In their recordings, they were able to identify some 32 "whistle contours"--variations in pitch that were often repeated. These whistle contours could correspond to word units in the porpoise language.

One of the critical factors in such a language, according to a report at the time by Dr. Gregory Bateson, now a researcher at Hawaii's Oceanic Institute, is whether the language is digital or analog. In an analog language, each whistle contour would represent a complete thought, like a sentence or an emotional state. If the language indeed turned out to be analog, this would mean the porpoise could communicate 32 sentences or complete thoughts--not a very intelligent language. On the other hand, if the language were digital--like ours--each whistle contour might represent only part of a word, corresponding to a syllable. In that case, the language could be composed of an almost infinite number of whistle-contour combinations, allowing for the communication of an equally large number of thoughts.

Dr. Bateson, however, now seems less optimistic. In a recent interview, he said linguists are no longer thinking of language in terms of analog and digital forms and that "the porpoise does not communicate with anything a linguist would call a language." Dr. Bateson declined to explain further, saying his research is not complete and that it would be unfair to draw conclusions on the basis of what he had done so far.

Another incomplete bit of research gives further tantalizing glimpses into porpoise communication. At Point Mugu, Dr. Jarvis Bastian has taught two porpoises, Buzz and Doris, to seemingly communicate with each other. Both porpoises were taught to press one of two underwater levers in response to a flashing or steady signal from an automobile headlight. Then Dr. Bastian set a barrier between them so one could not see what the other was doing, but they could hear each other. Finally, he flashed a signal to Doris. The object of the game was for Doris to tell Buzz which of his levers to push so that they could both receive a fish reward. The two animals mastered the trick and scored almost perfectly. But even Dr. Bastian acknowledges that the evidence at this point is equivocal. Doris could have been telling Buzz what to do. Or Buzz could have been guessing what to do simply by noting which side of the partition Doris' sonar signals were coming from as she beamed her sonar at a particular lever. Although the result is the same--Buzz pushed the correct lever--there could be a vast difference in the significance of the result, depending on how Buzz got the information. Did Doris say to Buzz in porpoise language, "Press the right lever, dearie"? Or did she just point to one side of the partition with her sonar or give some other simple cue?

Dr. Lilly is taking a totally different approach to porpoise communication. Instead of watching two porpoises talk to each other, he is trying to talk with them himself. The National Aeronautics and Space Administration was so impressed with his work a number of years ago that it granted him $87,000 a year to pursue the project. NASA's interest stemmed from its potential need to learn to communicate with alien species when our astronauts set down on distant, possibly inhabited planets. Dr. Lilly's prize subject is a bottle-nosed dolphin named Elvar with whom he has worked for several years. Elvar has learned to repeat a number of English phrases and number sequences in a high, Donald Duck-like voice. Whether he is actually communicating or just mimicking a sound is not known--although the latter hypothesis is certainly the more reasonable.

A scientist commenting on Dr. Lilly's work said that most porpoises are mimics. As we know, they are very social animals, tied up in the life of the school and very loyal to their society. Some schools are actually territorial: They stake out an area of the sea and guard it against all intruders--including porpoises from other schools. Mimicry, the scientist said, is probably used to develop dialectal passwords among the porpoises of a particular school.

Another scientist, Dr. René-Guy Busnel, director of France's Laboratoire d'Acoustique Animal, notes that spontaneous imitation of sounds of other species is common in nature, particularly among birds, "which incorporate signals of other species in the neighborhood in their own songs. They seem, however, to do nothing but imitate them; there is no integration of the signals into their own behavior."

In a different kind of porpoise experiment, a machine does the mimicking. The late Dr. Dwight Wayne Batteau of Tufts University constructed a device that transforms porpoise whistles into humanoid vowel sounds, and vice versa. When a porpoise whistle is fed into the machine, the machine makes a series of sounds that resemble the ancient Hawaiian language. If that same series of sounds is fed back into the machine, the machine will duplicate the original porpoise whistle. Thus, it is a kind of mechanical translator from one language mode to the other. Unfortunately, no important conversations have taken place through it so far. Some "nice command training" has resulted, however, reports a researcher.

All of the foregoing experiments are serving two functions in bringing man and porpoise closer to the hoped-for cooperative efforts of the future: First, they are seeking a common language so that human trainers may communicate their needs to the porpoise quickly and efficiently, providing the animal has the intelligence to understand those needs. And second, the experiments are providing at least an indication of the porpoise intelligence.

An exciting new experiment in porpoise intelligence was completed just a few months ago at the Oceanic Institute in Hawaii. Karen Pryor, considered by many of her colleagues the best porpoise trainer in the world, asked her porpoise to handle mental abstractions directly--perhaps the first time this has ever been tried. All previous tasks porpoises had been asked to do, no matter how complicated the end result, had been built up out of very simple "yes-no" conditioned-response actions tied together in a series by the trainer. The porpoise was taught a simple action by giving or withholding a reward. In the words of one researcher, "Current communication is binary--yes or no--but it eliminates inventiveness. The porpoise may perform the series of actions without ever understanding any of it, other than the fact that it will get a reward."

Mrs. Pryor took a different tack. She offered no rewards for previously learned tricks. She rewarded the porpoise only when it did something new. In effect, she was saying to the porpoise, "I'm tired of your old tricks. Invent a new trick." Such an idea is a pure abstraction. She succeeded in getting at least one porpoise to completely change its behavior pattern. That is, once it got the idea of what it was expected to do, it began doing everything differently. According to recent reports, the porpoise learned what it was expected to do quickly and then innovated all sorts of new tricks in rapid succession. If other porpoises can be made to perform similarly, the experiment will provide powerful support to those scientists favoring a very high estimate of porpoise intelligence. Heretofore, the only other creatures known to handle mental abstractions have been a few of the primates--such as rhesus monkeys, chimpanzees and man himself.

This high intelligence, if it exists, will also present certain problems in working with the porpoise--precisely the problems, in fact, that make the kamikaze scheme unworkable. Intelligence enables an animal to have a greater awareness of its environment and the dangers that lurk in the darkness beyond. Because of this awareness, scientists have had an exceedingly difficult time getting individual porpoises to perform in the open ocean--away from the comforting protection of their training pens.

In the 1965 open-ocean speed trials off Hawaii, for example, the first time a porpoise was enticed out into the ocean, she panicked and raced back into the home harbor. In subsequent attempts, she stayed close to the researchers' boat and refused to be left alone.

"Porpoises are full of fears," explained Dr. Norris. "Leave one alone in the ocean and it is scared pink. It constantly comes back for comfort." How did he know she was scared? Her eyes were wide and rolling and her teeth were actually chattering. She swam about frantically and often bolted either for the boat or for the harbor.

Dr. Norris noted that porpoises normally live in schools and their large numbers provide them with the feeling of safety they don't have when they are alone. He said the porpoise's lack of fear of man is typical of quite a number of marine animals. It is possible, he said, that terrestrial man is so alien to the porpoise that he is beyond the limits of normal porpoise fears. In support of this, Dr. Norris said porpoises were observed to become more wary of a man once he entered the water.

Fear of being alone probably will limit the use of porpoises to tasks in which the animal is working closely with man--or possibly with other porpoises. Obviously, it precludes sending out lone hunters to destroy enemy submarines or other distant targets. But potential peaceful tasks in cooperation with man exist in profusion. According to more than one scientist, the greatest limiting factor on man's undersea work is his difficulty in moving between the surface of the ocean and the ocean bottom--where he experiences much greater pressures. He must move slowly, carefully and not very often. The porpoise, on the other hand, has shown tremendous deep-diving capabilities. The animals have an exceptionally large blood volume, rich in hemoglobin capable of storing vast quantities of oxygen for long, deep dives. Furthermore, in tests now under way at Point Mugu and in tests completed off the coast of Oahu, Hawaii, the animals have demonstrated a prodigious stamina for making many deep dives in a relatively short period of time. This ability alone, say the scientists, will prove to be a tremendous boon to man at work beneath the sea.

There are other tasks, however, for which the porpoise could be used today, even at the present basic stage of research. Had a group of porpoises been previously trained for the task, for instance, they might have proved valuable in the search for the sunken hydrogen bomb off Spain two years ago. It would have been a simple matter to train a group of porpoises, carrying motion-picture or television cameras, to follow a sunken cable along the sea bottom: To search any area of the sea, the Navy would only have to sink a grid of cable in the prescribed area and then send down the porpoises to photograph it. The porpoises also could carry signal devices, such as a buzzer, controlled from the surface. They could be trained to perform various simple tasks at the sound of the buzzer. In the case of the bomb, for example, the animal might be asked to drop a floating marker at the sound of the buzzer. Men on the surface could monitor the porpoise's movement under water (via television) and sound the buzzer when it approached the bomb.

Obviously, a vast amount of work may be performed even today by trained porpoises under human control. The jobs are waiting. So is brother porpoise. If we can communicate the work in understandable terms, the porpoises will take it from there. As man turns more to the sea and learns more about his marine partner, that partnership will become more fruitful.