362 HOW CROPS GROW. 



The same authority gives the following account of the 

 microscopic changes observed in the starch-grains them- 

 selves, as they undergo solution. The starch-grains of 

 the bean have a narrow interior cavity (as seen in Fig. 

 65, 1). This at first becomes filled with a liquid. 

 Next, the cavity appears enlarged (2), its borders assume 

 a corroded appearance (3, 4), aud frequently channels 

 are seen extending to the surface (4, 5, 6). Finally, the 

 cavity becomes so large, and the channels so extended, 

 that the starch-grain falls to pieces (7, 8). Solution 

 continues on the fragments until they have completely 

 disappeared. 



Soluble Albuminoids. The insoluble proteids of 

 the seed are gradually transferred to the young plant, 

 probably by ferment-actions similar to those referred 

 to under the heading " Proteoses and Peptones," p. 100. 



The production of small quantities of acetic and lactic 

 acids (the acids of vinegar and of sour milk) has been 

 observed in germination. These acids perhaps assist in 

 the solution of the albuminoids. 



Gaseous Products of Germination. Before leav- 

 ing this part of our subject, it is proper to notice some 

 other results of germination which have been thought to 

 belong to the process of solution. On refemng to the 

 table of the composition of malt, we find that 100 parts 

 of dry barley yield 92 parts of malt and 2% of sprouts, 

 leaving 5 parts unaccounted for. In the malting pro- 

 cess, 1^ parts of the grain are dissolved in the water in 

 which it is soaked. The remaining 4 parts escape into 

 the atmosphere in the gaseous form. 



Of the elements that assume the gaseous condition, 

 carbon does so to the greatest extent. It unites with 

 atmospheric oxygen (partly with the oxygen of the 

 seed, according to Oudemans), producing carbonic acid 

 gas (C0 2 ). Hydrogen is likewise separated, partly in 

 union with oxygen, as water (H 2 0), but to some degree 



