TROPICAL TRIBES AND RACES 187 



with regard to marriage, sexual matters, outdoor life, and 

 exercise, are, so far as we could obtain evidence, practically 

 identical, and yet within these tribes, derived from the same 

 stock, living under similar climatic and tribal conditions, marked 

 differences in physique have developed. 



We hold that, while there may be other factors to account for 

 the superiority of the Tibetan and Nepalese Bhutia, diet and the 

 high level of protein metabolism he attains have a most important 

 influence in determining his manly form and energetic dis- 

 position. We have given details already of the dietaries of the 

 tribes inhabiting the hills of Bengal, and reference to them will 

 show that the more nutritive the diet, and the more assimilable 

 the protein element, the higher the tribe's place physically in the 

 scale of mankind. From actual work* done on representatives 

 of these tribes, it was found that the dietaries show a gradual 

 decline in the amount of nitrogen per kilo of body weight under- 

 going metabolism, and in accordance with this there is an 

 accompanying fall in the physique and general efficiency of the 

 different tribes from Nepalese and Tibetan Bhutias to Sikkim 

 Bhutias, and lastly to the lower classes of Nepalese. 



This can only be explained on the basis of differences in diet ; 

 the other factors put forward by Kellogg are common to all the 

 tribes. To anyone who has seen the powerful, muscular dandy- 

 carriers of Darjeeling, and the much slighter though compactly 

 built Nepalese, no evidence will be required to bring out the 

 superior physical development of the former ; and when along 

 with this we find the Bhutia attaining a much higher level of 

 protein interchange than the Nepalese, the conclusion that a 

 close relationship exists between the scale of protein metabolism 

 and the growth and development of the tissues of the body is 

 justifiable. The average values of the dietaries of these hill 

 people was found to be 



1. Tibetan Bhutias, Bhutias from Bhotan (dandy-carriers, ricksha-men, 



etc., who do the hardest work) : 



Protein, 175 grms., of which over 60 per cent, is derived from animal 

 source. 



2. Sikkim Bhutias (hard-working classes) : 



Protein, 131 grms., of which over 70 per cent, is derived from an 

 animal source. 



3. Nepalese Matwali (cultivators, coolies of poorer classes) : 



Protein, 110 grms., of which only a small percentage is derived from 

 an animal source. 



* Scientific Memoirs. Government of India, No. 38. 



