1892.] The Contemporary Evolution of Man. 461 



Degeneration is an extremely slow process; lioth in the 

 muscular and skeletal systems we find organs so tar on the 

 down grade that they are mere pensioners of the body, draw- 

 ing pay (i. e., nutrition) for past honorable services without 

 performing any corresponding work — the plantaris and pal- 

 maris muscles for example. Of course an organ without a 

 function is a disadvantage, so that the final duty <»t 

 tion is to restore the balance between structure and Junction 

 by placing it hors de combat entirely. ( >ne symptom ot decline 

 is variability, in which the organ seem- to he demonstrating 

 its own uselessness by occasional absence. As Humphrey 

 remarks: " The muscles which are mosl frequently absent by 

 anomalies are in fact those which can disappear with least 

 inconvenience, either because they can be replaced by others 

 or because they play an altogether secondary rob m the organ- 

 ism." The stages downward are gradual; the rudiment 

 becomes variable as an adult structure, then as a foetal struc- 

 ture; the percentage of absence slowly increases until it reap- 

 pears onlv as a reversion ; finally the part ceases even to revert 

 and all record of it is lost. This long struggle of the destruc- 

 tive power of degeneration, which you - 

 adaptive factor, against the protective power of heredity tsthe 

 most striking feature of the law of Repetition. (See Galton s 

 similar principle of Regression in Anthropology). 



A careful study of our developing, degenerating, rudimen- 

 taland reversional organs amply demonstrates that man i> 

 now in a state of evolution hardly less rapid, I believe, than 

 that which has produced the modern horse from 

 five-toed ancestor. As far as I can see the only 

 our evolution should be slower than that ot the am-mnt hoi,. 

 is the frequent intermingling of races, wh 

 resolve types which have specialized into more & f 

 types. Wherever the human species has been isolate or i 

 long period of time divergence of character is very mai 

 will be seen in some of the races I refer to belo*. 



To lighten the long catalogue of facts, 

 authors I shall fremiMitb, dlude to hnlnt. but wil i-<>ou ■ 

 consider it for the time as associatronal rather than casual. 



