62 



A FEW WORDS ABOUT MOTHS. 



55. Chrysalis of Ameiicaa 

 Silk Worm. 



silk is said to be quite brilliant, but a little coarser and not so 

 strong as that of the Bombyx mori. The Perny silk worm is 

 extensively cultivated by the Chinese in Manchouria, where it 



feeds on the oak. Its silk is 

 coarser than that of the com- 

 mon silk worm, but is yet fine, 

 strong and glossy. Bengal has 

 furnished the Tussah moth, 

 which lives in India on the oak 

 and a variety of other trees. It 

 is largely raised in French and 

 English India, according to 

 Nogues, and is used in the manufacture of stuffs called corahs. 

 The last kind of importance is the Arrhii^y silk worm, from 

 India. It has been naturalized in France and Algeria by M. 

 Guei'iu-Meneville, who has done so much in the application of 

 entomology to practical life. It is closely allied to the Cynthia 

 or Ailanthus worm, with the same kind of silk and a similar 

 cocoon, and feeds on the castor oil plant. 



The diseases of silk worms naturally receive much attention. 

 Like those afflicting mankind, they arise from bad air, resulting 

 from too close confinement, bad food, and other adverse causes. 

 The most fatal and wide-spread disease, and «ue which since 

 1854 has threatened the extermination of silk worms in Europe, 

 is the pebrine. It is due to the presence of minute vegetable 

 corpuscles, which attack both the worms and the eggs. It 

 was this disease which swept off thousands of Mr. Trouvelot's 

 Polyphemus worms, 

 and put a sudden ter- 

 mination to his im- 

 portant experiments, 

 the germs having 

 been implanted in 

 eggs of the Yama-' 

 mai moth imported 

 from Japan by M. 

 Guerin-M eneville ^^' Cocoou of Americau Silk Worm, 



and which were probably infected as they passed through Paris. 

 Though the disaster happened several years since, he tells us 

 that it will be useless for him to attempt the raising of silk 

 worms in the town where his establishment is situated, as the 

 germs of the disease are most difficult to eradicate. 



