146 EVOLUTIONISTS OF THE EIGHTEENTH CENTURY. 



his application of his theory. He proceeds to dis- 

 cuss the wants of animals, arranging them first 

 under the head of sexual characters, as horns, 

 spurs, developed for purposes of combat and pro- 

 curing the females. Thus, the horns of the stag 

 have not been developed to protect him from the 

 boar, but from other stags. He here misses the 

 idea of the sexual selection of the horns developed 

 as ornaments to the male. Other organs, he says, 

 are developed in the search for food. Cattle have 

 acquired rough tongues to pull off the blades of 

 grass ; and of these and similar organs he says : 

 " All which seem to have been gradually pro- 

 duced during many generations, by the perpetual 

 endeavour of the creatures to supply the want of 

 food, and to have been delivered to their posterity 

 with constant improvements for the purpose re- 

 quired." Again he says : " There are organs devel- 

 oped for protective purposes, diversifying both the 

 form and colour of the body for concealment and for 

 combat." He here definitely unfolds the idea of 

 protective colouring. 



He closes his long argument by pointing out the 

 close gradations in Nature from the higher to the 

 lower forms, and the substantial similarity between 

 the animal and vegetable kingdoms in their modes 

 of generation or reproduction, and concludes as 

 follows : 



" From thus meditating upon the minute portion of time in 

 which many of the above changes have been produced, would it 



