RESERVE MATERIALS OF PLANTS. 121 



and an albumose. The former is readily soluble in 10 to 

 15 per cent, sodium chloride solutions and coagulates on 

 heating to about 70 C. The albumose is nearly identical 

 with Kuhne's deutero-albumose and appears to be the same 

 body as the same observer discovered to exist in the 

 latex of the Papau {Carica papaya). It will be described 

 later. 



As already mentioned, besides aleurone grains, proteid 

 has been found in definite bodies in the cells of the tuber of 

 the potato, where it exists in the shape of crystals of cubical 

 form. These are insoluble in 10 per cent, solution of 

 sodium chloride, but dissolve at once in saturated solutions. 

 They belong, therefore, to Weyl's vegetable vitellin. Zoller 

 has found (10) in the potato also some vegetable myosin, 

 which is soluble in 10 per cent, sodic chloride solution. 

 This is probably in the form of amorphous proteid in the 

 protoplasm of the cells, as the microscope does not reveal its 

 presence. Other observers have pursued the same line of 

 investigation, and with the better means of examination that 

 have been devised in recent years have made still further 

 determinations of the nature of the proteids of the seed. 

 Chittenden and Osborne (11) in 1891 discovered that the 

 maize contains more than one globulin and a mixture of 

 albumins, the latter being soluble in distilled water, and the 

 solution coagulating on boiling, therein showing a difference 

 from the albumoses, which are not so changed. Besides 

 these they describe a peculiar proteid which differs from all 

 others so far found by being insoluble in water, but soluble 

 on warming with dilute alcohol. To this they have given 

 the name of zein. The action of alcohol on the grains was 

 shown by Vines to be somewhat peculiar, many of the crys- 

 talloids being insoluble in saturated solution of sodium 

 chloride until after treatment with alcohol, when they dis- 

 solved readily. 



The occurrence of proteid in some such forms as some 

 of these was indicated by Zacharias (12) in sieve tubes, 

 where it became coagulated on heating. Fischer (13) 

 made a similar discovery in Cucurbita. Zacharias de- 

 scribes his proteid as insoluble in water or neutral salts, 



