REARING SILKWORMS. 63 



MULBERRY TREES. 



The foundation of silk-production is the mul- 

 berry tree, as from it is developed the best 

 quality, as well as the greatest quantity, of silk, 

 in proportion to the amount of labor expended. 



There are many varieties of the mulberry. 

 Each kind produces a quality of silk correspond- 

 ing to the quality of leaf-food coming from the 

 tree. Some yield a very coarse silk, and others 

 an exceedingly fine quality. Some yield a larger 

 quantity of silk to the pound of leaves, than 

 others. , But all varieties of the mulberry yield 

 more and better silk to the quantity of leaves, 

 than any other plant or tree, so far as yet known 

 to silk-cult urists. 



Silkworms require food containing four sub- 

 stances ; viz., fibrous, resinous, saccharine, and 

 watery. Th^ fibrous JiolcU-tJhe leaves intact 

 while the worins~are feeding; the saccharine and 

 watery substances nourish, the worm; and the 

 resinous substance yields the silk. 



In proportion as these" substances are con- 

 tained in the leaf-food, they are valuable. 



The white mulberry, in all its varieties, is 

 considered the best silk-producer. Its principal 

 varieties are the Morus Japonica, Morus alba, 



