ARGUABLY, THE popularity of giant pandas owes much to Theodore Roosevelt, progenitor of the Teddy Bear cult, and to the black patches of fur on their faces that make their not particularly large eyes look so big. Psychologists tell us that faces with big eyes appeal to something deep in the human soul. Popular the panda certainly is, and as emblem of the World Wildlife Fund, the quintessentially Chinese mammal is immediately identifiable by everyone. Yet no other large mammal -- they weigh up to 140 kilos -- has been more mysterious or less studied up to the present time.

Although Chinese literature mentioned the giant panda as early as 3000 B.C., the Western world first heard of its existence in 1869 and the late 19th-century museum trophy mentality at once set about hunting and killing "the black and white bear that eats copper and iron," metal-gobbling bear though it wasn't. With the first live panda arriving in the United States in 1936, the killing gave way somewhat to collecting for zoos, but almost no scientific work on the species was done until the 1950s when Chinese scientists began observing wild pandas. In the 1960s and '70s a meager quantity of information on studies of captive giant pandas emerged, but essentially the animal, with perhaps a total population of about 1,000 in existence, remained an uninvestigated enigma with virtually nothing known about its life and habits.

It took the flowering of umbrella bamboo in the forests of northern Sichuan between 1974 and 1976 to change things. Normally bamboo reproduces vegetatively by sending up shoots from its rhizomes. But once in a long while, wch may be 40 or even 100 years, the bamboo breaks into flower, produces seeds and dies back over vast areas. That is what happened in the mid-1970s, and the rare disappearance of its principal food source meant starvation for the giant pandas. At least 138 died. Over the millennia when the phenomenon had previously occurred, the pandas had probably coped with the situation by migrating to areas where the bamboo had not flowered. Now, with habitat destruction and hunting having reduced the panda distribution in China to but six small areas along the edge of the Tibetan plateau, the spectre of imminent extinction of the species was plainly raised. Alarm bells rang around the scientific world and among the public at large, both within and beyond the borders of China.

In 1979 an ambitious scheme for cooperation between Chinese scientists and the World Wildlife Fund in studying the conservation needs of the pandas was launched, and unlike many of is kind, the international committee charged with getting things rolling acted speedily and did things instead of talking. On the World Wildlife Fund side, George B. Schaller of the New York Zoological Society led the research, concentrating mainly on one of the six panda areas, that of the Wolong Natural Reserve where a special research center was set up. Now Schaller and his Chinese colleagues have trekked out of the forest bearing the gospel about the panda. They present the first comprehensive study of the giant panda ever undertaken and what an intriguing story they have to tell.

Well-written and fascinating for lay panda-lover and professional zoologist alike, the book documents the search for fundamental information that will be of practical benefit in conserving the unique beast. It asks and intelligently answers, as far as currently possible, the key questions.

The giant panda is an anachronism -- neither bear nor raccoon, Schaller and Co. advise after clearly analyzing the hotly disputedtheories of evolution of the species. It lives a mainly solitary life in difficult terrain and is one of the most inefficient utilizers of food known to science.

The work of the Sino-American team gives us the fruits of extensive study of feeding habits, movement patterns, population dynamics and social behavior in the wild. Bamboo eater he may be for 99 percent of the time, but there is evidence here that the panda sometimes takes a fancy to meat in the form of golden monkeys or musk deer.

Radio tracking reveals that our black and white friend is a home lover who seldom travels more than 500 meters in a day. And an account of a female panda who calmly delivered and suckled a baby only a stone's throw from a logging operation will cause a few teeth to grit in the handful of panda-owning zoos around the world where breeding has been none too successful.

For many years to come, or at least until Schaller and his collaborators return again from the forest with more revelations, this book will remain the bible for all who love pandas and can appreciate thorough, practical zoological research of the highest order.