Monthly Mlcrnscoplcai'] 
Journal, May 1, 1869. J 
Silhivorm Cultivation. 
307 
and care, also obtained a large produce in cocoons ; but the moths 
which came from them contained corpuscles. He had not isolated 
Ms chambers. 
This, then, is why in some localities, as the Apennines, in 
Dalmatia, and in Istria they have always good crops of cocoons 
and sound eggs. The localities are much more isolated than ours 
are. The hatching-grounds are at the summit of hills and in 
conditions most favourable to avoid contagion. 
See what has occurred this year in Istria. For several years I have 
myself examined the eggs cultivated by MM. Villanova de Farra, 
not far from Trieste (they rear some thousands of ounces), and they 
have so far recognized the importance of my predictions, that they 
wished this year to carry out experiments on the subject. I there- 
fore sent to them M. Gaddi, who has been accustomed to this sort 
of microscopic work in my laboratory. He set out with his micro- 
scope to Istria, and visited several localities. In the course of his 
travels he examined fifty-four different lots of cocoons, commencing 
with the examination of the chrysalides, in order to reject those 
which were diseased. 
Out of fifty-four different batches, only five (Nos. 8, 11, 17, 35, 
and 49) exhibited 10 per cent, of corpuscles, and therefore these pre- 
sented favourable chances of obtaining healthy moths. It is neces- 
sary to state that even in the same batch of chrysalides there might 
be different proportions of healthy and diseased specimens, according 
to the degree of maturity. The chrysalides just formed partook of 
the condition of the worm ; these, which were many days older, 
partook more of the condition of the moth. In one case (No. 36) 
the chrysalides just formed showed only 4 per cent, of infected 
specimens ; but, after some days, they presented as much as 70 per 
cent, of corpusculated specimens. Thus we may lay down the 
proposition that the chrysalides just formed exhibit the disease much 
in the same degree as the corresponding egg ; those, however, which 
are near their transformation present the disease in a much more 
marked degree. Of the several lots examined, three only gave 
indications of healthy produce. The results of the examinations of 
these is given in the following Table : — 
Chryaslides. 
Moths. 
Eggs. 
Number of 
Per- 
Number of 
Per- 
Number of 
Per- 
individuals 
Diseased. 
centage of individuals 
Diseased. 
centage of 
individuals 
Diseased. 
centage of 
examined. 
diseased. 
examined. 
diseased. 
examined. 
diseased. 
No. 11 
31 
? 
0 
141 
3 
2 
116 
0 
0 
17 
32 
3 
133 
1 
0-75 
205 
0 
0 
35 
80 
1 
1-25 
1268 
18 
1-5 
215 
0 
0 
