BOOK IX.--The subject of the eighth book is continued, with an account

of the relations in which animals stand to each other, and especially the friendship and hostility of different species; and these are for the most part referred to the nature of their food, and their mode of procuring it. The notices of fish are not so numerous as those of other groups: this would necessarily arise from the difficulty of observation. At the conclusion of the book, an essay on bees and their congeners is given at considerable length.