182 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



tain "granulosc," and tliat it is easy to prove that they consist of pure "cellulose," for 

 if Lugol's solution be used instead of iodine the skeletons in a short time become brownish, 

 then a copper-red, and finally gradually go over into violet. Thus, he states, the actions 

 of the plant ferment, like those of saliva, at first cause the granulose of the starch-grains 

 to dissolve. The cellulose of the starch-grain of the bean was not so insoluble, because 

 after prolonged action of the ferment the grains become more transparent and delicate, so 

 that the grains finally can be distinguished only when stained; their contours, which at first 

 are distinct, become obscure, and the skeletons finally disappear altogether. Powerful fer- 

 ments brought this about in 4 to 5 days. 



In the germinating seed of Phaseolus multiflorus the same phenomena were observed, 

 except that frequently some of these grains were found which did not dissolve from the 

 inside but were dissolved evenly, so that the transparency of their skeletons gradually 

 became visible throughout the entire grain. Similar aj^pearances were also observed in 

 artificially dissolved grains where the action of the ferment was slow and weak, although 

 an actual formation of a skeleton never took place. This deviation from the ordinary 

 process of solution, Baranetzky believes, is probably due to a non-penetration of the 

 ferment evenly into all parts of the grain. The fresh starch-grains of the scarlet bean 

 almost always show, he states, a complicated system of furrows and fissures, of which 

 several extend to the periphery. In ordinary cases the ferment probably forces its way 

 through these fissures into the inside of the grains and begins its action before the out- 

 side layers have been in the least affected by it. Accordingly, it is found that the inner 

 furrow usually follows the direction of the fissure, and widens toward the inside to reach 

 the periphery of the grain at these places. 



Wliile the dissolution of the granulose takes place almost uniformly from within 

 outward, the grains of some of the seeds of Phaseolus deviated from this rule. In these 

 cases the granulose disappeared very unevenly, and the remaining skeletons, although 

 consisting of pure cellulose, were nevertheless usually substantial, and their contours 

 almost as well-defined as those of the intact grain. These skeletons, however, were finally 

 dissolved by the prolonged action of the ferment. Baranetzky states that this would seem 

 to prove that the starch-grains of the same plant may differ in their cellulose content, 

 since it does not seem likely that these deviations can be attributed to the differences in 

 the solubility of the granulose and the cellulose of the different starch-grains. 



QuERCus Pedunculata. 



This starch behaves similarly to that of Phaseolus. The process always begins in 

 the inside of the grain, with the difference that the outlines of the gradually increasing 

 clear spot are not distinct, and gradually pass into the grain substance. As the process 

 of solution reaches the periphery, only the granulose disappears, the cellulose remaining 

 behind in the form of a sharply outlined skeleton, as in Phaseolus. The cellulose reaction 

 is not so easily produced as in Phaseolus. Lugol's solution causes a yellowish color at 

 first, which finally goes over into copper-red and violet. The cellulose skeletons are also 

 completely dissolved. 



SoLANUM Tuberosum. 



In the grains of potato starch the process of solution begins at the periphery and 

 extends to the inside of the grains, where small round or irregular clearly outlined spots 

 make their appearance. Seen in profile, these spots appear like canals entering into the 

 inner part of the grain and are filled with a soft transparent substance. Fine but distinct 

 lamellae may often be seen in the latter. Sometimes those places on the outside of the 

 grain at which erosion takes place simultaneously are numerous and irregular, and grad- 

 ually merge into each other, so that the surface of the grain is covered with complicated 

 markings. The eroded places grow deeper toward the inside of the grain, and then widen 



