63 PROPERTIES OF STARCH 



of blood ; substances which may be entirely dispensed 

 with in their nourishment in the adult state. In the 

 young of carnivorous birds, the want of all motion is 

 an obvious cause of diminished waste in the organized 

 parts ; hence, milk is not provided for them. 



The nutritive process in the carnivora thus presents 

 itself in two distinct forms ; one of which we again 

 meet with in the graminivora. 



XIII. In the class of graminivorous animals, we 

 observe, that during their whole life, their existence 

 depends on the supply of substances having a compo- 

 sition identical with that of sugar of milk, or closely 

 resembling it. Every thing that they consume as food 

 contains a certain quantity of starch, or gum, or sugar, 

 mixed with other matters. 



The most abundant and widely-extended of the sub- 

 stances of this class is amylon or starch ; it occurs in 

 roots, seeds, and stalks, and even in wood, deposited 

 in the form of roundish or oval globules, which differ 

 from each other in size alone, being identical in chemi- 

 cal composition. (11) In the same plant, in the pea, for 

 example, we find starch, the globules of which differ in 

 size. Those in the expressed juice of the stalks have a 

 diameter of from 2 m to T | of an inch, while those in the 

 seed are three or four times larger. The globules in 

 arrow-root and in potato starch are distinguished by 

 their large size ; those of rice and of wheat are remark- 

 ably small. 



It is well known that starch may be converted into 



