CHAPTER VI. 
REPRODUCTION. 
‘It has been said in Chapter IV that the first condition of success in 
raising Silk-worms is to ‘‘ procure good eggs.” The object of the present 
chapter is to describe the most approved processes of producing such 
eggs. 
Were it not for the diseases to which the Silk-worm is subject, the 
old, simple processes of egg production might still be followed, and 
even now, unless the egg producer is able and ready to undertake 
the microscopical examination required by the Pasteur system, it is 
needless to observe the more complex rules for the isolation and ex- 
amination of the moths. 
The simple process formerly employed in all sericultural countries 
consisted in stringing the cocoons and letting the moths couple, as in 
the modern process. <A sheet was then hung up with the lower edge so 
turned as to form a trough into which any badly gummed eggs might 
fall. After uncoupling, the females were placed upon the sheet and per- 
mitted to lay their eggs promiscuously. The only precaution taken 
against disease was in the selection for reproduction of lots of cocoons 
whose larvie had shown no signs of any malady, and which were 
themselves of first quality. From what has been said it will at once be 
seen that pébrine contracted after the fourth molt and the slow form of 
flaccidity due to the presence of chain-ferment are not thus guarded 
against. The modern system has a deeper, more scientific basis, and 
aims to guard against these. 
The Pasteur system of microscopical selection.— As we have seen, pébrine 
and flaccidity are the only diseases which it is necessary to guard against 
jn selecting eggs. If pébrine or flaccidity have appeared in a positive 
form in the larve, either through the external or internal symptoms de- 
scribed in the last chapter, no further examination need be resorted to, 
as the stock will evidently be unfit for reproduction. The most im- 
portant and positive sign of the latter disease to be looked for is languor 
at the spinning time. If a greater degree of certainty is desired, or if 
the egg-producer has not had the opportunity of observing the rearing 
of the worms, a miscroscopical examination of the chrysalis may be re- 
sorted to. In flaccidity this examination should be confined to the 
stomach, where the chain-ferment to be sought for is more easily found. 
M. Pasteur gives the following directions for extracting this organ: 
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