PBEFACE. II 



to each other, and especially the friendship and hostility 

 of different species ; and these are for the most part re 

 ferred to the nature of their food, and their mode of pro 

 curing it. The notices of fish are not so numerous as those 

 of other groups : this would necessarily arise from the diffi 

 culty of observation. At the conclusion of the book, an 

 essay on bees and their congeners is given at considerable 

 length. 



BOOK X. This book, in all probability erroneously as 

 cribed to Aristotle, is occupied with a treatise on the 

 causes of barrenness in the human species. It appears 

 to be rather a continuation of the seventh book, which ends 

 abruptly ; but it is well placed at the end, as no genuine 

 work of our author. 



