FUNCTIONAL VARIATION 99 



functions have been deranged by some cause, external or inter- 

 nal, and whose activities have been diverted to the production of 

 abnormal but characteristic tissue with " no typical termination 

 to its growth." 



Nearly all tissues of the body 1 are subjected to this derange- 

 ment of their ordinary functions, resulting in the suspension of 

 all activities except that of growth, which proceeds with the 

 "energy of embryonic development" and continues indefinitely. 



Though often supplied with special blood vessels and a system 

 of nerves, these growths are entirely functionless and therefore 

 useless to the body. Being parasitic they are always a drain 

 upon its resources, and often from their nature or position they 

 constitute a real menace to its existence. 



A tumor represents a bit of differentiated body tissue that 

 for some reason or other has abandoned its characteristic func- 

 tions, cut loose from all restraints of heredity, set up an inde- 

 pendent existence of its own at the expense of the colony of 

 which it has been a respectable and dependable member, and 

 has now devoted all its resources to growth, which, as has been 

 said, proceeds with the energy of embryonic development, result- 

 ing in nothing but functionless masses of living matter, strongly 

 suggesting a reversion to primitive undifferentiated tissue. 



Under conditions not well understood all sorts of abnormal 

 growths may appear. In this way an antenna may appear where 

 an eye ought to be, 2 or it may end in a foot instead of a feeler. 3 

 ^The writer knew a young lady of culture and of no little natural 

 beauty except for the fact that, growing from one cheek, was a 

 tuft of coarse black hair three or four inches long. Her normal 

 hair was brown and her complexion clear. What functional dis- 

 turbance could have given rise to such a growth is as mysterious 

 s it was unfortunate. 



Ossification is a natural process, but under the influence of 

 excessive strain it may proceed to an abnormal extent, as in 

 spavin, where the entire hock joint becomes solid through the 

 ossification of the fluid thrown out as the result of injury. 



1 Muscles, fatty tissue, connective tissue, bone, cartilage, nerves, glands, blood 

 vessels, the covering of the brain, etc. 



2 Bateson, Materials, etc., p. 151. 3 Ibid. pp. 146-147. 



