322 PHYSIOLOGY AT THE FARM. 



dom are the tuberous roots and the seeds of grasses and of 

 leguminous plants. The stem also of certain palms and palm- 

 like plants, as the cycadacese, abounds in starch. 



It was, not many years ago, believed that the absence of 

 starch was characteristic of the animal kingdom, or that no 

 animal product contained starch. On this point new views 

 have now arisen, though the subject is still involved in much 

 obscurity. Certain it is that the corpuscular variety of the 

 Corpora amylacea, known as a morbid deposit in various parts 

 of the animal body, as in the brain and prostate, shows 'a re- 

 action almost identical with starch, giving a blue colour with 

 iodine. 



Among nutritive substances starch holds a prominent place. 

 In many respects, however, further investigation as to the place 

 it holds as a nutriment is imperatively required. Like sugar, 

 as before remarked (p. 313), it is held by Liebig to be merely 

 a respiratory food. By others, again, it is believed to be 

 one of the sources of the fat which becomes deposited in 

 the tissues of healthy animals. 



Again, Dumas denies that animals have the power of form- 

 ing fat, contending that all the fat that manifests itself in the 

 animal body is derived from oily particles in the food. To 

 add to the difficulty, Jacquelain insists that both starch and its 

 granules contain from 0.24 to 0.31 per cent of nitrogen. 



In the mean time the most probable state of the case seems 

 to be, that starch, while it is chiefly a respiratory food, is a 

 source of the fat which becomes deposited to serve as fuel 

 against emergencies ; and, moreover, that it is not unlikely a 

 minute portion of some nitrogenous or proteine compound is 

 contained in starch granules. 



There is some ground for believing that starch is not 

 effectually digested unless previously boiled. According to 

 Kaspail, starch is not actually nutritive to man until it has 



