The Biology Labs have two bronze rhinoceroses on the outside and 5000 live rats on the inside. The rats undoubtedly have a better time of it.

They live in a brick-glass, fluorescent-lighted palace with individual and family-size eages. When a biologist operates on them, an anaesthetist always stands by with a tankful of other. The rats lives are regulated according to the most scientific methods of bodily discipline.

From Rack to Rack

The females live in circles. They start in the male rack. Then they go to the pregnancy rack, and then to the maternity rack, and then to the resting rack, and then back to the male rack, and start all over again. At an opportune moment their babies are weaned and deployed among the researchers.

This way the Department grinds out 15,000 rats a year. And they use every one of them. They also use 100 guines pigs, 50 rabbits, 25 chickens and ducks, and--two dozen monkeys.

Gophers Can't Have Kids

Using guines pigs, for example, Professor Frederick L. Hisaw has discovered relaxin, a chemical now known to exist in the human body. His search started several years ago when scientists discovered, much to their chagrin, that pocket gophers were physically incapable of having children. The female pelvis was much too small.

Hisaw explained the seeming inconsistency by finding that relaxin causes widening of the pelvis when a female is pregnant. He is now studying the chemistry and workings of this hormone, and is using other hormones in monkeys to reproduce artificially the conditions of pregnancy.

Sex Life of an Amoeba

Professor L. R. Cleveland is more interested in the sex life of smaller animals, minute protozoa that live in the bodies of insects. Usually the amoebae reproduce by splitting in half, but inside insects they find a chemical that changes them into males and females.

That's why the protozoa lives there. By reproducing sexually they get new gene structure in their offspring, and can improve biologically. The whole subject throws light on how sex began, and why.

Down the ball from the mice and monkeys is a room full of moth pupas, with their brains cut out. The pupa is the animal inside a cocoon; and Assistant Professor Carroll M. Williams has found that it will live indefinitely but not grow when its brain is removed. He has kept pupas for months in animated suspension and then put their brains back, and they started growing where they left off.

Method in Kindness

Williams has a reason for all this, of course. His field is merphogenesis--the development of different kinds of animals. If he can discover what makes pupas grow, he will know what makes humans grow too.

The other line of Williams research also deals with insects, and the unexplained mystery of how they fly. Men can contract their muscles only 10 times a second, but some insect wings hit frequencies of 1000. Biologists have never understood how they do it and in his attempts to find out Williams has built such weird instruments as a machine that measures the horsepower output of a fruitfly.

Perplexed Monkeys

The Bio Labs have a stock of plants as well as animals. On the top floor, less than 100 yards long, is one of the world's strangest greenhouses. It contains:

A rubber plant from Brazil; a vanilla tree; a plant that curls up when you touch it; a flower that eats ants; sugar cane; and a monkey-puzzle tree--supposed to be the one tree that monkey's can't climb.

It's probably the only greenhouse where weeds and orchids grow side by side, and where people pay more attention to weeds. It's certainly one of the few greenhouses where plants wear bandages. Professor Kenneth V. Thimann put them on after injecting hormones into the stems to see how growth was affected. His investigation of plant galls may lead to new information on animal cancers.

In the field of plants, Professor Paul C. Mangelsdorf has recently developed a custom-built corn for New England gardens and named it the Dwarf Harvard Hybrid. The corn, now on the market, is ideally suited to New England gardens and climate. Mangelsdorf's hybrid corns are proving revolutionary for the world's food supply.

The biologists have dozens of other projects. Some are digging for fossils in Vermont; some are trying to find how insects got their wings; some are learning how the human eye sees; and one man is studying the effects of sewage disposal in the ocean. There's a project for every professor, and there are 32 professors.

To carry on these activities, the Biology Department and the two Institutes of Botany have acres of facilities all over North America, including an Arboretum in Jamaica Plain, a garden in Cuba, a forest in Petersham, and a concrete tank in Woods Hole full of diatoms, molluses, and sea water. But the most amazing place of all is the 400-room laboratory on Divinity Avenue that carries a two-foot cucumber