5 5 o THE POPULAR SCIENCE MONTHLY. 



Again, the skeleton presents important characters. We ought, at 

 least, to examine the breast, the pelvis, the hones of the limbs, etc. ; 

 but we must leave this subject, to say a word on the soft parts. 



Regarded in the two extremes of humanity, the white European 

 and the negro, the nervous system presents a fact which it is impor- 

 tant to point out. With the first, the nervous centres the brain and 

 spinal cord are relatively more voluminous. In the second, on the 

 contrary, it is the expansions from the centres the nerves which are 

 more voluminous. 



The circulatory apparatus presents a balance somewhat analogous. 

 With the white, the arterial apparatus, which carries the blood to the 

 organs, is relatively more developed than the venous apparatus that 

 draws the blood toward the heart. 



The blood of the negro, studied in his native country, is more vis- 

 cous and darker colored than that of the white. That of the creole 

 negro of New Ox-leans is, on the contrary, paler and more aqueous, 

 and recalls the blood of the anaemic. So, a simple change of habitat 

 sometimes modifies a human race in this most profound character in 

 this liquid pabulum destined to penetrate and nourish all parts of the 

 body. 



III. Physiological Characters. I shall dwell briefly on the 

 physiological characters, and only point out two general facts, of which 

 you will easily see the importance : 



As regards all the great periods of life and all the great functions, 

 there is an almost complete identity among all men, to whatever race 

 they belong. 



When tbis resemblance is not apparent, the cause is not in the na- 

 ture of the races, but in the influence of conditions of existence. This 

 is well proved by the fact that races the most widely separated resem- 

 ble each other completely w r hen they are exposed to identical condi- 

 tions through a change of habitat. So, the precocity of the negro has 

 been cited as distinguishing this race from European nations ; but, 

 when white people live for generations in hot countries, they take on 

 the same peculiarity. The negress and the English Creole of the isles 

 of the Gulf of Mexico are just alike in precocity. 



On the contrary, the study of secondary functions shows that they 

 vary from one group to another, and sometimes very widely. But, 

 then, also, we see that the environment, the manners, the habits, etc., 

 are the cause of these variations ; and, again, we see races the most un- 

 like come to resemble each other so much as to be confounded together. 

 There are hunters of English and French descent who have the senses 

 of sight and hearing as quick and sharp as the red-skins. 



In concluding, the study of physiological characters strongly attests 

 the fundamental unity of the human race, by throwing light on the 

 marvellous flexibility of our organism. 



