DEGENERATION, 281 
generation is taking an important part. Degeneration . 
is known among men as well as among the lower animals 
Fic. 23.—Adult Sacculina attached by root Fic. 24.—Section of 
processes to the crab. (After Lang.) mature Sacculina. 
(After Lang.) 
or plants. It is governed by similar laws. The condi- 
tions of human degeneration are essentially those of 
degeneration on lower forms. The causes which will in 
the long run transform a crab to a Sacculina will make 
paupers of the descendants of parasitic men. As it is 
the mind that makes the man, the essence of human 
degeneration is failure of the nervous structures and 
functions. It means decline in the accuracy of thought 
and the veracity of action. The soundness of the ma- 
-chinery of response to external conditions determines, 
‘in general, the life and character of man. Degeneration 
in man is therefore “a morbid deviation from the moral 
.type,” so far as nerve functions are concerned. 
Personal degeneration comes naturally with the pe- 
-tiod of. old age. The compound animal or “colonial 
