INCREASED AND DIMINISHED NUTRITION. 



95 



loped the adipose and muscular are most influenced by 

 altered diet. It may be said that the elementary parts of 

 these tissues exhibit greater variation in activity than those 

 of other textures. In some men and animals it would 

 appear that the elementary parts of adipose tissue take up a 

 larger share of nutrient matter in proportion than those of 

 other tissues j while, on the other hand, the elementary 

 parts of the glandular excretory organs are, in other indivi- 

 duals, the most active. The elements which in the first 

 would slowly become an integral part of the body, as fat 

 and other tissues, would in the last quickly escape as 

 carbonic acid, water, and other substances, in the excre- 

 tions. It is not possible to say why one set of tissues 

 should be most active in one individual, and another set in 

 another individual, any more than we can explain why a 

 particular kind of food, which is most easily assimilated by 

 one person or animal, should be useless or injurious to 

 another. 



As there are in the body many different tissues to be 

 nourished, and many different substances in the blood 

 which may nourish them, it is necessary to consider what 

 particular constituents of the blood are principally con- 

 cerned in the nutrition of the different textures. The 

 opinion seems to have been very generally entertained that 

 certain substances in the blood were destined for the nutri- 

 tion of particular tissues, while other textures, it was sup- 

 posed, selected from the fluid, constituents of a different 

 character; for instance, it has been maintained that the 

 red blood-corpuscles were specially concerned in the nutri- 

 tion of the nervous and muscular tissues, while the white 



