in CHEMICAL VARIATION 



It may be argued that such instances are not very 

 convincing : they concern very different species and 

 genera ; how can it be proved that such important 

 variations occur within the same species, for there is 

 the point ? To this the answer is easy to give, and 

 if we turn to any given species, we cannot fail to 

 notice important differences. Take the human species, 

 for instance, and consider the differences between man 

 and woman, then those between the races of man, 

 and finally between the different men of the same 

 race. 



As an instance of chemical difference between man 

 and woman, here are the percentages of the principal 

 components of bony structures in man and woman of 

 the same age, after Milne-Edwards : 



Woman. Man. 



Phosphate of Lime 62*15 5&'3~ 



Carbonate -. 4-52 9-98 



Organic Substances 33'33 3170 



Inorganic 66*67 68*30 



And it must be noticed that the differences vary 

 according to the age of the patients, and even to the 

 side of the body. While in the young the proportion of 

 inorganic substances is smaller than in the adult, the 

 bones of the right side of the body contain more 



Sur r Action de quelques Poisons de la Serie cinchonique sur le Cardnus 

 maenas (ibid. 1891), where similar facts are recorded. 



