UTILITARIAN DOCTRINE 209 



constitutions would succeed best under different climates. 

 With cattle susceptibility to the attacks of flies is correlated 

 with colour, as is the liability to be poisoned by certain 

 plants; so that even colour would be thus subjected to the 

 action of natural selection. Some observers are convinced 

 that a damp climate affects the growth of the hair, and that 

 with the hair the horns are correlated. Mountain breeds al- 

 ways differ from lowland breeds ; and a mountainous country 

 would probably affect the hind limbs from exercising them 

 more, and possibly even the form of the pelvis; and then 

 by the law of homologous variation, the front limbs and the 

 head would probably be affected. The shape, also, of the 

 pelvis might affect by pressure the shape of certain parts of 

 the young in the womb. The laborious breathing necessary 

 in high regions tends, as we have good reason to believe, 

 to increase the size of the chest; and again correlation 

 would come into play. The effects of lessened exercise to- 

 gether with abundant food on the whole organisation is 

 probably still more important; and this, as H. von Nathusius 

 has lately shown in his excellent Treatise, is apparently one 

 chief cause of the great modification which the breed of 

 swine have undergone. But we are far too ignorant to specu- 

 late on the relative importance of the several known and un- 

 known causes of variation ; and I have made these remarks 

 only to show that, if we are unable to account for the char- 

 acteristic differences of our several domestic breeds, which 

 nevertheless are generally admitted to have arisen through 

 ordinary generation from one or a few parent-stocks, we 

 ought not to lay too much stress on our ignorance of the pre- 

 cise cause of the slight analogous differences between true 

 species. 



UTILITARIAN DOCTRINE, HOW FAR TRUE: BEAUTY, HOW 



ACQUIRED 



The foregoing remarks lead me to say a few words on the 

 protest lately made by some naturalists, against the utilitarian 

 doctrine that every detail of structure has been produced for 

 the good of its possessor. They believe that many structures 

 have been created for the sake of beauty, to delight man or 



