The cottontail first made its appearance as Palaeolagus in the Oligocene era. By 1923, some 500,000,000 of the species dwelled in the United States, by Ernest Seton's estimate. 85% of them do not live to complete their first year; they have a potential life span, in comfortable captivity, of ten years. ""Not built for defense,"" they must maintain their numbers by an extensive breeding season. Even so, by the time the hunters are on their trail in November, 60% of the year's crop has come a cropper to predators (the fox, the weasel, the owl, and even such unlikely enemies as the crow and the blacksnake), poaching, highway fatalities or natural causes (the rabbit is unhappy host to numerous parasites). Still, it is America's #1 small game species: Remington figures 29% of all ammunition is fired at the cottontail. Mr. Rue easily transfers this and much other information-- about the play of the senses, about breeding and feeding habits--in an engaging little book with photographs (not seen here) to match the text. He was written previously of Deer and Beaver (The World of).