TRANSLOCATION OF PLASTIC MATERIAL 239 



translocated. The calcium present would form insoluble crys- 

 tals of oxalate which are always found after the synthesis of pro- 

 teids. The relative share of the nucleus and cytoplasm in the 

 synthesis have not been ascertained. 1 



306. Translocation of Plastic Material. Substances such as 

 the carbohydrates, formed, or stored, in some special organ of the 

 plant are often conveyed long distances through the body to 

 tissues where they are used for various purposes. The carbo- 

 hydrates in the leaf are transported to the root, and the material 

 accumulated in underground storage organs and seeds is carried 

 to the newly developed shoots and branches.. In all cases the 

 material to be moved is converted into some form readily diffu- 

 sible. Carbohydrates are converted into glucose or maltose, 

 although some translocation may occur in other forms, and pro- 

 teids are hydrolyzed, or broken up into amides, and again reformed 

 into albuminous bodies upon reaching the tissue to which they 

 were attracted. The transportation of food, or plastic material 

 from one organ to another is largely a matter of osmotic attrac- 

 tion, although the physical process is under the control of the 

 protoplasts, which have the power of varying the permeability of 

 the plasmatic membranes from time to time. The use of any 

 plastic substance, or its conversion into an insoluble form in any 

 cell, reduces the concentration of the solution in the cell in ques- 

 tion, and a supply flows in to equalize the osmotic balance, and in 

 this way a stream of carbohydrate may flow from the leaf to the 

 root. The conversion of insoluble or indiffusible into soluble 

 diffusible form is generally effected by the action of enzymes 

 (See Enzymes). Carbohydrates are formed in the leaves about 

 ten times as rapidly as they may be removed by translocation in 

 ordinary species. During the period of illumination the amount 

 which might not be diffused from the cell in which it was formed 

 is condensed into starch by the action of pyrenoids, or certain 



1 Hanstein, B. Ueber Eiweisssyn these in griiner Phanerogamen. Jahrb. Wiss. 

 Bot. 33 : 417- I899- 



Schulze, E. Ueber Eiweisszerfall und Eiweissbildung in der Pflanze. Ber. Deut. 

 Bot. Ges. 18 : 36. 190-1. 



