113 HOW CROPS GROW. 



Pflamenheims, p. 104). Iti form they sometimes imitate 

 crystals quite perfectly. Fig. 21, a; in other cases, b, 

 they are rounded masses, haying some crystalline planes 

 or facets. They are soft, yield easily to pressure, swell 

 up to double their bulk when soaked in weak acids or 

 alkalies, and their angles have not the constancy peculiar 

 to ordinary crystals. Therefore the term crystalloids, i.e., 

 having the likeness of crystals, has been applied to them. 



As Cohn first noticed {Jour. fiXr Praht. Ghem., 80, p. 

 129), crystalloid aleurone may be observed in the outer 

 portions of the potato tuber, in which it invariably pre- 

 sents a cubical form. It is best found by examining the 

 cells that adhere to the rind of a potato that has been 

 boiled. In Fig. 31, a represents a cell from a boiled 

 potato, in the center of which is seen the cube of aleurone. 

 It is surrounded by the exfoliated remnants of starch- 

 grains. In the same figure, h exhibits the contents of a 

 cell from the seed of the bur reed {Sparganium ramo- 

 sum), a plant that is common along the borders of ponds. 

 •In the center is a comparatively large mass of aleurone, 

 having crystalloid facets. 



As already stated, the proteids in the crystalloid alen- 

 rones of hemp, castor-bean and squash have ibhe chemical 

 characters of globulin. The aleurone of the Brazil-nut 

 {Bertholletia) and that of the yellow lupin contain, ac- 

 cording to Hartig and Kubel, 9.4% of nitrogen which 

 corresponds to some 50 or 60% of proteids. 



Weyl obtained from the Brazil-nut a very pure amor- 

 phous vitellin with 18.1% of nitrogen. The vitellin of" 

 Brazil-nut, castor-bean, and of hemp and squash seeds has 

 been recrystalized from salt solutions by Schmiedeberg, 

 Drechsel, Griibler and Rifcthausen. According to Vines, 

 seeds of lupin and peony yield a myosin to salt-solution, 

 and sunflower seeds, after treatment with ether to remove 

 oil, yield a globulin with the properties, of myosin, but if 

 alcohol is used, the proteid has the character of vitellin. 



