28 The Descent of Man 



This affords us a good example of hasty and inconclusive 

 speculation. Surely it would be as rational to suppose that 

 the arctic species h^^ gained their coats as that the tropical 

 species had lost theirs. But over-hasty conclusions are, we 

 regret to say, the rule in Mr. Darwin's speculations as to 

 man's genealogy. He carries that genealogy back to some 

 ancient form of animal life somewhat like an existing larval 

 Ascidian ; and he does this on the strength of the observa- 

 tions of Kowalevsky and Kuppfer. He assumes at once that 

 the similarities of structure which those observers detected 

 are due to descent instead of to independent similarity of 

 evolution, though the latter mode of origin is at least 

 possible,^ and can hardly be considered improbable when we 

 reflect on the close similarity independently induced in the 

 eyes of fishes and cephalopods. 



Quite recently, however, observations have been published 

 by Dr. Donitz,^ which render it necessary, at the least, to 

 pause and reconsider the question before admitting the 

 Ascidian ancestry of the Vertebrate sub-kingdom. 



We now come to the consideration of a subject of great 

 importance — namely, that of man's mental powers. Are they, 

 as Mr. Darwin again and again affirms that they are,^ difierent 

 only in degree and not in kind from the mental powers of 

 brutes ? As is so often the case in discussions, the error to 

 be combated is an implied negation. Mr. Darwin implies 

 and seems to assume, that when two things have certain 

 characters in common, there can be no fundamental difference 

 between them. 



^ See Professor Rolleston's Address at the Liverpool Meeting of the British 

 Association, 1870. 



" See Journal fiir Anatomie und Physiologie, edited by Reichert and 

 Dubois, Berlin. 



^ * There is no fundamental diflFerenee between man and the higher 

 mammals iu their mental faculties.' — Descent of Man, vol. i. p. 35. 



