The Descent of .Alan 



vided with branchiae [gills], with the two sexes 

 united in the same individual, and with the most 

 important organs of the body (such as the brain 

 and heart) imperfectly or not at all developed. 

 This animal seems to have been more like the 

 larvae of the existing marine Ascidians than any 

 other known form. 



The greatest difficulty which presents itself 

 when we are driven to the above conclusion on 

 the origin of man is the high standard of intel- 

 lectual power and of moral disposition which he 

 has attained. But every one who admits the 

 principle of evolution must see that the mental 

 powers of the higher animals, which are the same 

 in kind with those of man , though so different in 

 degree, are capable of advance nent. Thus 

 the interval between the mental powers of one 

 of the higher apes and of a fish, or between those 

 of an ant and scale-insect, is immense; yet their 

 development does not offer any special difficulty; 

 for with our domesticated animals the mental 

 faculties are certainly variable, and the varia- 

 tions are inherited. No one doubts that they 

 are of the utmost importance to animals in a 

 state of nature. Therefore, the conditions are 

 favourable for their development through natural 

 selection. 



The same conclusion may be extended to 

 man; the intellect must have been all-im- 

 portant to him, even at a very remote period. 

 as enabling him to invent and use language, to 

 make weapons, tools, traps, etc., whereby with 

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