490 NUTRITIONAL REQUIREMENTS 



Doubtless much depends upon the quality of the vege- 

 table food. It is well known that the occurrence of pellagra 

 has by many been attributed to an almost exclusive maize 

 diet; it is worth noting that zein (a protein substance which 

 represents the bulk of the proteid material in the maize 

 grain, and which is distinguished by the absence of the tryp- 

 tophane group, of glycocoll and lysin) has been proved to 

 be badly suited as a continuous food for guinea pigs and 

 mice. 20 



Mechanical Preparation of Vegetable Food. Hans 

 Friedenthal has recently directed attention to a new side of 

 the vegetarian problem, which, to the author, seems to pre- 

 sent a phase of great interest. In a general way, we are 

 only able to get the good out of those parts of plants which 

 are stocked with reserve substances (like fruit, roots and 

 tubers) ; while those very parts of plants which are richest 

 in protein, the leaves, cannot be utilized either in the raw 

 or after cooking. It seems, however, that it is possible by a 

 method of very fine mechanical comminution to pulverize 

 dried green plants in such a way that the greater part of the 

 cell walls are broken up and the cell contents made available 

 for the action of the digestive juices. By this method we 

 can obtain the green plants in the form of a fine powder, 

 which, in passing through the intestine, does not induce an 

 increased peristalsis as the ordinarily ingested gross vege- 

 table structures regularly do, and which is digested with the 

 greatest ease. Infants less than six months of age, to whom 

 hitherto greens could not be given in any way, have been 

 allowed to drink spinach-powder or carrot-powder with the 

 milk from a bottle, without the least manifestation of diges- 

 tive disturbances. It certainly is a matter of considerable 

 importance to be able, with a spoonful of the powder dis- 



m 8. Baglioni, Rend. Accad. Lincei, IT, 609, cited in Centralbl. f. Physiol., 

 22, 782, 1908; V. Henriques (Copenhagen), Zeitschr. f. physiol. Chem., 60, 

 105, 1909; E. Abderhalden and C. Funk, Zeitschr. f. physiol. Chem., 60, 418, 

 1909. 



