Nov. 1, 1864.] THE TECHNOLOGIST. 



RESTORATION OF THE SILKWORM. 159 



As long as the reservoirs contain gum, the thickness of the silk will 

 be the same whether the worm is diseased or not, provided always that 

 the worms are of equal size ; and that simply owing to the regulating 

 organ above mentioned. The quality of the silk comprises thickness of 

 fibre, tenacity, and elasticity, and where the secreting glands are not 

 affected by disease, this quality, from worms equally well fed, will be 

 the same, even where the general health of the one is far inferior to th e 

 other ; indeed, it is the quantity, rather than the quality, of the silk 

 that is affected by the maladies under which the worms are now 

 labouring. The cocoons reared in Oudh by Colonel Clark, and pro- 

 nounced by Mr. Cope in epistold to be " the finest he had seen in India," 

 produced, on being reeled, a silk of precisely the same quality as that 

 at Umritsir, and by my Mussooree cocoons reared from Mr. Cope's 

 supply of diseased eggs in 1862, and which, as cocoons were abso- 

 lutely worthless, there being little or no silk in them. Dr. Bonavia'a 

 cocoons, raised in Oudh in 1863, from seed furnished by Mr. Cope, 

 yielded a silk in no respect inferior to the above, although the pound 

 of silk requiring 5,200 cocoons to produce it proved how terribly defi- 

 cient was the quantity of gum secreted. In cases where the glands are 

 affected by disease, or where the leaf has not contained a proper propor- 

 tion of silk-yielding matter, no silk at all will be secreted, and the 

 worm will either die as such, or become a pupa without spinning. 

 Many cases of this kind occur in all the broods, whether monthly or 

 annual. 



To talk, as some do, of coarse leaves producing a coarse silk, and 

 therefore recommending the use of such as are thin and tender, is at 

 once to prove non-aquaintance with the anatomy of the insect and 

 ignorance of the whole art of nourishing the worm, since, as already 

 pointed out, the thickness of the silk fibre is regulated by Nature, and a 

 thin fibre produced by a worm, which, like B. mori, ought to yield one 

 of a certain thickness, is a positive proof of the presence of disease, 

 indicates the decreasing size of the orifices, consequent on the deteriora- 

 tion and degeneracy of the worm. The orifices in the lip being of a 

 regulated size, no extra-natural coarseness of fibre can be produced, and 

 no coarseness of leaf could ever make the fibre thicker than Nature 

 intended it to be, or than those orifices were capable of admitting, simply 

 because it is a well-ascertained tact that " a camel cannot pass through 

 the eye of a needle." 



(To be continued. ) 



