316 PRESENT PROBLEMS IN EVOLUTION AND HEREDITY. 



From the typical mammalian standpoint man is a degenerate 

 animal; his senses are inferior in acuteness; his upright position, while 

 giving him a sni^erior aspect, entails many disadvantages, as recently 

 enumerated by Clevenger,* for the body is not fully adapted to it; his 

 feet are not superior to those of many lower Eocene plantigrades; his 

 teeth are mechanically far interior to those of the domestic cat. In 

 fact, if an unbiassed comparative anatomist should reach this planet 

 from Mars he could only pass favorable comment uj>on the perfection 

 of the hand and the massive brain. Holding these trumps, man has 

 been and now is discarding many useful structures. 1 refer especially 

 to civilized man, who is more j>rodigal with his inheritance than the 

 savage. By virtue of the hand and the brain he is nevertheless the 

 best adapted and most cosmoj^olitan vertebrate. The man of Nean- 

 derthal or Spy, with retreating forehead and brain of small cubic 

 capacity t was limited both in his ideas and his powers of travel; yet 

 he was our sui)erior in some points of osteological structure. But the 

 X^eriod of Neanderthal was recent compared with that in which some 

 of our rudimentary organs were serviceable, such as the vermiform 

 appendix or the panniculiis carnosus| muscle. These rudiments in 

 turn are neogenetic when we consider the age of the two antique 

 sense organs in the optic thalamus, the remnants of the median or 

 pineal eye and the pituitary body, both of which were undoubtedly 

 present, and probably useful, in the recently discovered Silurian iishes. 



I mention these vestiges of some of the first steps in creation to illus- 

 trate the extraordinary conservative power of heredity (which is even 

 more forcibly seen in our embryological development), partly also to 

 show how widely our organs differ in age. Galton has com^iared the 

 human frame to a new building built up of fragments of old ones; ex- 

 tend this back into the ages and the comparison is complete. 



Development, balance, degeneration. — It is probable tliat none of our 

 organs are absolutely static and that the apparent halt in the develop- 

 ment of some is merely relative, as where a fast train glasses a slow one. 

 The numerous cases of arrested evolution in nature are always con- 

 nected with fixity of environment, an exceptional condition with man, 

 and we have ample evidence that some organs are changing more rap- 

 idly than others. 



Adaptation to our changing circumstances is mainly effected by the 

 simultaneous development and degeneration of organs which lie side 

 by side, as in the muscles of the foot or hand; in terms of physiology, 



* Disadvantages of tlie Upiiglit Position, ai'tic]<> in American Xaturalist, January', 

 1884, vol. xviii. p. 1. 



tThe remarkable skulls and skeletons which have recently been discovered at 

 8py remove all doubts as to the normal, i.e., racial character of the famous Nean- 

 derthal skull, which were entertained by Quatrefages and others. See Fraipont 

 and Lohest, Archives de Biolof/ie, 1887, p. 697. 



tThis is an epidermal or twitching muscle in the quadrupeds. 



