TABOO AND GENETICS 8i 



ductory or explanatory. The extent to which 

 the sociological problem involved is linked up 

 with general biological considerations like 

 natural selection, adaptation and specialization 

 will be summarized in a separate chapter. 



Earlier female maturity and puberty, as well 

 as lighter structure, have already been accounted 

 for b}^ the metabolism, especially of the calcium 

 salts. These have also been shown to be the 

 key fact in the monthly periodicity of the mam- 

 malian female. Nearly all of the anatomical 

 and physiological sex differences catalogued 

 by such pioneer workers as Ellis, Ploss, Thomas 

 and Bucura are simply what we should expect 

 from the less active and in some ways peculiar 

 metabolism of woman. 



Among such differences are the size and 

 shape of bones and other body structures, the 

 more plentiful haemoglobin in male blood during 

 the reproductive period, and such blood pecu- 

 liarities as the production of more carbonic acid 

 or the higher specific gravity in the male. The 

 greater percentage of fat as compared with 

 muscle in women (19), if it is generally true, is 

 what we should expect from a lower metabolism 

 and a tendency to store materials. The long 

 list of diseases which are more or less sex-limited 

 (20 ; 14, pp. i6of. ; 18) are largely endocrine. 

 Even those which do not primarily concern the 

 internal secretory system would be expected to 



G 



