PREFACE. 



In the present volume I have collected together some 

 of my recent observations on the senses and intelli- 

 gence of animals, and especially of insects. 



While attempting to understand the manners and 

 customs, habits and behaviour, of animals, as well as for 

 the purpose of devising test experiments, I have found 

 it necessary to make myself acquainted as far as possible 

 with the mechanism of the senses, and the organs by 

 means of which sensations are transmitted. With this 

 object I had to look up a great number of memoirs, in 

 various languages, and scattered through many different 

 periodicals ; and it seemed to me that it might be inte- 

 resting, and save others some of the labour I had to 

 undergo myself, if I were to bring together the notes 

 I had made, and give a list of the principal memoirs 

 consulted. I have accordingly attempted to give, very 

 briefly, some idea of the organs of sense, commencing 

 in each case with those of man himself. 



