CONCLUDING REMARKS. 449 



firmation to the doctrine that each and every modifica- 

 tion of the type of the sum of all the positive characters 

 of a species, is fraught with physiological injury which 

 beyond a very narrow limit entails the extinction of 

 the line of the individuals so modified. 



So, even if all the individuals of every species in the 

 world had departed from the types of their respective 

 species, and even if there were no form extant, which 

 realized the perfect type of its species, the type of 

 each species would not be involved in doubt; for it 

 is ever susceptible of ascertainment. Interbreed the 

 individuals, and the evil effects, consequent upon such 

 process, will furnish a perfect register of the amount of 

 departure which they have made from the original, 

 normal form. By careful breeding, modify a human 

 being, until he closely resembles a monkey — in the 

 length and proportion of his arms and legs, in the con- 

 tour of his head, in his facial angle, in the character of 

 the ribs, &c, — place the man and a monkey side by 

 side; and if structural differences alone are to be taken 

 into account, as Darwin holds, there would be a 

 close similarity between the two. But, when physio- 

 logical tests are applied, there is revealed a wide 

 distinction. Breed either of the two, with one of 

 its own kind, similarly modified, and it will respond, 

 and give a faithful register of the distance it has re- 

 moved from its normal type. The human being will 

 be prolific of the greatest possible evils; thus evi- 

 dencing the enormous amount of modification which 

 it has suffered. The monkey, on the other hand, 

 will be free from all display of evil effects; or, possi- 



