PLANTS. 89 



the special purpose, as is seen in the amraouiacal fermentation 

 of urine. " M. Musculus has shown that we may obtain from 

 altered urine a soluble ferment. Upon adding to it highly-con- 

 centrated alcohol a precipitate is formed which may be filtered 

 and dried. This precipitate, not at all organized, transforms 

 urea into carbonate of ammonia. A temperature of 80 (176 

 Fah.), destroys it. This diastase appears, then, to be a secretion 

 of the micrococcus urea, and perhaps the role of the bacteria is 

 limited, in the phenomena of fermentation, to the formation of 

 this secretion alone. The ammoniacal transformation of urine 

 would, consequently, enter into the group of fermentations by 

 the varieties of diastase." (Magnin on Bacteria, page 142.) 



The proof here given of the production of a true digestive 

 body, or diastase, by the micrococcus urea is sufficiently positive; 

 but M. Musculus must be wrong in his supposition that the 

 " role of the micrococcus is limited to this one function ; " for, if 

 the organism does not appropriate from the results of its diges- 

 tion, wherewithal does it live. It may be that we have here an 

 example of superabundant digestion, which, as a matter of fact, 

 is to be expected when the natural condition is the diffusion of 

 the digestive solvent through masses of fluid material. But the 

 organism must live by remoleculizations within itself, and elim- 

 inate waste products. Therefore, the explanation is incomplete. 



It has also been shown that the first changes which albumen 

 undergoes in decomposition are similar to digestion. It is first 

 converted into soluble forms, partly peptones, and afterward 

 converted into other forms. 



PLANTS. 



When we turn our attention to the higher forms of plant 

 life, we are beset with many difficulties. The botanists, it 

 seems, have, as a rule, endeavored to explain the growth of 

 plants from the chemical standpoint, and have almost univer- 



