
236 THE INSECT WORLD. 
very beginning of the rearing, and increases in intensity at each — 
age, so that the number of worms able to enter regularly into the 
moult becomes smaller and smaller. We are still in a state of 
utter ignorance as to the cause of this last affection, which has 
occasioned, for the last ten years, incalculable losses in the rear- 
ing houses, which threatens the silkworm with complete destruc- 
tion, and which in the meanwhile has ruined the unfortunate 
countries of the Cévennes, the principal seat of sericiculture in 
France. 
During the fifth age, the worms become large so quickly that 
on the fifth or sixth day they are obliged to be moved away from 
each other on the litter. The délitement must be made every two 
days, or, indeed, every day now, on account of the enormous 
amount of the excrement; and, at the same time, a good venti- 
lation must be constantly maintained. The temperature of the 
room should now be kept to 24°, without ever exceeding this 
degree of heat. When it is perceived that the worms wish to 
ascend or mount, there are placed on the tables, at certain distances 
from each other, little sprigs of heather, or very dry branches 
of light wood. 
When the worms begin to mount into the heather, one must 
encabaner, that is to say, form with these branches little hedges 
5) 

| UE 
YL INN 

i oT TTT 
Fig. 213.—Sprigs of heather arranged so that the silkworms may mount into them. 
curved back like a hut or cradle, the openings of which are, 
on an average, seventeen inches or so (Fig. 213). At the 
expiration of twenty-four hours, all the good worms have 
mounted. The laggards who remain under the cabanes are 
taken off by hand, and placed on a table, which is immediately 
encabaned. 


