ii2 SCIENCE PROGRESS. 



described by various writers, apparently showing no simi- 

 larity to those of the animal organism. Legumin, congliitin 

 and other names were applied to them, and their ultimate 

 analyses showed but little agreement. The application of the 

 various methods of examination which threw so much light 

 upon the proteids of the animal body has, however, estab- 

 lished the fact that they are of the same nature and of pretty 

 nearly the same composition as the latter, the discrepancies 

 at first so prominent being ascertained to be due to the 

 modes of preparation or extraction. 



Besides these proteid bodies, however, other nitrogenous 

 compounds have been identified, chiefly, though not entirely, 

 confined to the fluid sap which is in the living cells. These 

 are of a much simpler composition ; they include asparagin, 

 glutamin, leucin, tyrosin, and other crystalline bodies which 

 from their chemical constitution are grouped together under 

 the name of amides. In their origin they are in many cases 

 to be regarded as derived from the more stable proteids, and 

 are indeed the chief form in which the latter are transported 

 from place to place. They have, however, another possible 

 source, being in many cases the expression of an incomplete 

 constructive process and capable of conversion into the pro- 

 teids themselves, from which later they are again recon- 

 structed. 



Some amount of nitrogenous reserve materials may also 

 be found in some of the glucosides, such as amygdalin, pre- 

 sent in the seeds and other parts of certain of the Rosacea?, 

 and myrosin, so prominent in many of the Cruciferse. 



Of non-nitrogenous reserve material we find the great- 

 est amount to be carbohydrate. Here we find starch and 

 its derivatives, cellulose, various kinds of sugar, inulin, and 

 glycogen, giving a great variety of forms and great differ- 

 ences in amount in various plants. Next in importance 

 come the glucosides, less uniformly distributed but still 

 occurring very widely in particular groups of plants. Fats 

 and oils are of common occurrence in many fruits and seeds, 

 sometimes found alone, sometimes with carbohydrates in the 

 same cells. 



Besides these substances, of the meaning and import of 



