The modern zoo the modem zoo is an educational institution carefully planned and arranged to bring to the visitor the story of the animal world. the methods of exhibiting animals have undergone certain drastic changes in the last century. originally, animals were kept either in cages or in open pits the cage type of exhibit remains the backbone of the average zoo display, but the pit type, with many variations, is also very popular. at the beginning of the 20th century, a new trend in zoo exhibits was introduced in germany and was soon adopted in many other parts of the world, particularly in america, this was the so-called barless cage exhibit. in barless cages the animals are presented to the public with the neccessary barriers hidden or ecessary camouflaged, like, for example, on an "island" surrounded by either a dry or water-filled ditch. many zoos are slow in adopting the new trend in animal exhibits, the newer zoos, however, are incorporating the modern exhibit design into their plans. the most up-to-date exhibits not only feature barless cages they try to reproduce the animals' native habitats, including vegetation and rock formations. often quite extensive records are kept in modern zoos the studies cover the longevity, diet requirements, medical histories and so on of various animals. zoo records are primarily of interest to other zoos however, some of the studies originating at zoos have proven of value to the medical profession as well. — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — - l. but also pay close attention to the setting of the displays. 2. because many zoos conduct serious studies in zoology. 3. where the original idea was greatly developed. 4. where zoo directors are thinking ofsetting up new animal exhibits. 5. because it involves rebuilding the animal quarters. 6. but animals may be grouped according to habitat. 7. where the public could look down on them.