206 INITIATIVE IN EVOLUTION 



intolerable house of bondage if there were not many things that 

 matter not as well as things that matter, and there is reason to 

 believe that in the process of the making of man and a vast 

 number of forms below him there is a large field of structures, 

 parts and organs, where things that matter not are to be found. 

 One strange province of this realm is the colouration of animals 

 in certain regions where no eye ever can see the colour or can take 

 any heed of the markings, treated very fully many years ago by 

 Mr. Beddard in Animal Colouration. 



Unstriped muscle arises, as the striped variety does, from the 

 mesoblastic muscle-plate and appears in nearly all organs, blood- 

 vessels and skin, and as trade is said to follow the flag, so a develop- 

 ment of new unstriped muscles must speedily be found in every new 

 structure of the regions where unstriped muscle is found. The 

 skin is the simplest, and less complicated by the presence of other 

 structures than vessels and organs, where it also exists, but where it 

 trespasses too much on the territory of selection for my immediate 

 purpose. A small band of this muscle called an arrector, or erector, 

 pili is attached to most, if not all, of the third of a million hairs 

 which cover the skin of man, and is inserted into that side of each 

 hair which forms an obtuse angle with the plane of the skin. This 

 tiny structure is endowed with the quality of contracting in response 

 to certain stimuli falling on the skin, so that it causes the hair to 

 which it is attached to stand erect instead of sloping, and incidentally 

 squeezes some of the secretion out of the sebaceous gland which 

 lies in each angle. The human skin thus possesses about a third 

 of a million minute muscular bands and shows no sign of parting 

 with this old gift from a lower hairy stock, and whatever value, if 

 any, their function be to their possessor they show a remarkable 

 readiness to perform it efficiently. It makes their existence and 

 persistence no clearer to call them vestigial, for one only thus 

 throws the question of their origin much farther back. Undoubtedly 

 they come from afar and were in full development in the earliest 

 hair-clad mammals, so an ancestry reaching back to Monotremes 

 or Marsupials is not to be lightly set aside. The raw material was 

 undoubtedly formed in response to stimuli conveyed to the brain, 

 and the earliest appearance of muscles which erected the hairs 

 must have been wholly insignificant either upon the survival or 

 comfort of the possessors. 



A Remarkable Example. 



The arrectores pili exhibit very little evidence of control or 

 interference from the action of the brain, but there is one region 



