PREFACE. xxxvii 



change of specific character, especially if it should be in the 

 ascensive direction, there might be associated powers of pene- 

 trating the problems of zoology so far transcending those of our 

 present condition, as to be equivalent to a different and higher 

 phase of intellectual action, resulting in what might be termed 

 another species of zoological science. 



With the present psychical and structural characteristics of the 

 human species, it may be reasonably concluded that those of other 

 existing species, especially of the distinctly marked vertebrate 

 classes, will be, at least, concurrent and co-enduring ; and, in that 

 sense, we may accept the dictum of the French zoologist: — ' La 

 stabilite des especes est une condition necessaire a l'existence de 

 la science d'Histoire Naturelle.' At the same time, indulging with 

 Lamaeck in hypothetical views of transmutative and selective 

 influences during reons transcending the periods allotted to the 

 existence of ourselves and our contemporaries, as we now are, we 

 may also say: — l La nature n'offre que des individus qui se suc- 

 cedent les uns aux autres par voie de generation, et qui provien- 

 nent les uns des autres. Les especes parmi eux ne sont que 

 relatives, et ne le sont que temporairement,' 



