46 INTRODUCTION. 



Now, all this may be, and much is, certainly true ; but it 

 is most assuredly a most partial mode of looking at the re- 

 lations of animals, even in a natm-al history and economical 

 point of view. We orchnarily employ the term relationship 

 to designate that bond of community existing amongst the 

 members of a family ; but there are numerous other species 

 of alliances to which we may also give the general term of 

 relations. And it is upon these undeniable relations, affini- 

 ties, analogies, resemblances — call them as you will — that 

 the classification of all animals is founded. And the more 

 perfect our knowledge of any animal, in all its states, and 

 in its relations to all other animals, the more correctly are 

 we enabled to give due weight to every peculiarity, whether 

 structural or functional, which it exhibits; and thus to 

 trace its more or less contiguous relations mth other animals. 

 Again, if we look at the habits of insects, we find some ex- 

 hibiting a similar predaceous economy ; others are vegetable 

 feeders; some attack particular species of animals; others 

 particular species of plants. Now each of these groups of 

 species mil, both from economy and from structure dependent 

 upon economy, exhibit more close relations amongst their 

 respective members, than the species belonging to groups 

 possessing opposite habits. Hence we may be induced to 

 affirm, as has been done by a celebrated writer. Dr. Fleming, 

 that we shall have as many systems of animals as there are 

 variations of function. And thus, animals differing from 

 each other, except in one isolated particular, are thought to 

 be more nearly related together than they are to other 

 species, to which, in all their other particulars, they are 

 more intimately allied ; but this also appears to us to be an 

 equally incorrect and partial view of looking at nature. We 

 have given too great a weight to such an isolated peculiarity. 

 I will endeavour to illustrate this view of the subject by a 

 reference to the recently published volume of the Count de 



