!Cj8 PHYSIOLOGY OF NUTRITION 



§2. Proteins.— The proteins are chemically the most complicated constitu- 

 ents of the plant. 1 They accumulate to the greatest extent in the protoplasm 

 of resting cells and cells where physiological activity is just beginning. The 

 diagrams of Fig. 85 represent stages in the development of a dicotyledonous 

 seedling: 7 is a young embryo, 77 is a developed embryo, and 777 is a germinated 

 seedling. The parts rich in proteins are shown in black. These parts are the 





Fig. 85. 



-Diagrams showing stages in the development of a dicotyledonous seedling, and 

 distribution of proteins. (After Sachs.) 



youngest organs of the plant, and are either in the resting condition or are just 

 beginning to grow. The shaded areas represent parts containing smaller 



1 For the literature of proteins see: Hammarsten, O., Lehrbuch der physiologischen Chemie. 4 te Aufl. 

 Wiesbaden, 1899. [Idem, A text-book of physiological chemistry. Tr. by J. A. Mandel from 8th Ger. ed. 

 (7th Eng. ed.) New York, 1914.] Haliburton W. D. A text-book of chemical physiology and pathology. 

 874 p. London, 1891. See p. m-142. Cohnheim, Otto, Chemie der Eiweisskorper. 31S P- Braun- 

 schweig, 1900. Griessmayer, Victor, Die Proteide der Getreidearten. Heidelberg, 1897. (Czapek, F., 

 Biochemie der Pflanzen. 3 te Aufl. 3 v. Jena. 1922-1925.) Abderhalden, E. ( Lehrbuch der physiologis- 

 chen Chemie in dreissig Vorlesungen. Berlin, 1906. Idem, Handbuch der biochemischen Arbeitsmethoden. 

 8v Berlin, 1910-1915. [Euler, 1908-1909. [See note 1, p. IS7-] Hofmeister, 1901. [See note 2, p. 157.] 

 Grafe, 1914. [See note a, p. 83.] Haas and Hill, 1921. [See note 3, P- 6.] Osborne, Thomas B., The 

 vegetable proteins. London and New York, 1909. Plimmer, R. H. Aders, The chemical constitution of 

 the proteins. London and New York. 1908.] 



