THE WONDER OF LIFE 513 



ing, may induce functional changes even in the skeleton, 

 which are there for life. 



These modifications are sometimes indifferent, so far as 

 we can judge, as regards the welfare of the organism ; and 

 though they are almost always attempts at effectiveness 

 on the part of the structure affected, they may be pre- 

 judicial to the organism as a whole. In the case of a goldfish 



Fig. 80. — -Underside of a young flounder, showing pigmentation after 

 exposure to light from beneath. (After J. T. Cunningham.) 



shut up for years in total darkness, there is degeneration 

 of the eye, which is no doubt a modification on the minus 

 side. Yet the degeneration considered by itself may be 

 regarded as a quite effective response to the abnormal 

 conditions involved. The inflammation that follows an 

 invasion of microbes into the body may lead on to death, 

 but it is none the less an effective response on the part of 



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