DIVIDING TUBERS FOE "SETS." 39 



floor, is the best place for the work ; the operation is rather 

 a tedious one where large quantities are required, as each 

 tuber has to be divided singly by 

 the hand; the "sets," however, 

 may remain for a week or two 

 without suffering injury, which 

 gives an opportunity for profitably 

 occupying any wet day that may 

 occur with the work. In the divi- 

 sion of the tuber the cut surfaces 

 are apt to "bleed," and if thrown 

 carelessly into a heap, and left for 

 a few days, the exuded^moisture causes the mass to heat, to 

 the great injury of the germinating powers of the "sets/' 

 This may be readily avoided by dipping the incised sur- 

 faces into lime, chalk, or gypsum, which, uniting with the 

 moisture from the divided cells, forms a coat on the surface, 

 and thus prevents further loss by bleeding or evaporation. 

 The latter (gypsum) is the best substance to use, as it is 

 more effective for the immediate purpose for which it is in- 

 tended, while at the same time it supplies, as far as it goes, 

 an important manurial substance to the growing plant. 



Where whole tubers are used in planting, the small ones 

 are usually picked out of the heap and laid aside for this 

 purpose. These are generally known by the name of 

 "chats," and as they are not very saleable in the markets, 

 they are thus rendered available for seed purposes. In this 

 case, the tuber, small though it be, may possess as many 

 germs or "eyes" as the large, fully-matured tuber used for 

 dividing into "sets/' and consequently will produce as 

 many young plants. But here the great difference arises 

 between their relative powers of reproduction. The 

 young plant lives upon its parent until its own powers of 

 supply are sufficiently established to enable it to send 

 down its roots into the soil in search of inorganic sub- 



