LEPIDOPTERA. 235 
- When they awake out of this last sleep the attendant — 
should continually be on his guard, as it is then that diseases 
break out. The worms suffering from these different diseases 
have received different names. There are besides the /utsettes, 
_ the arpians—that is to say, worms that have exhausted all their 
energy in the work of the last moult, and have not even strength 
to eat ;—the yellow or fat worms, which are swollen, of a yellowish 
colour, and which very easily die. The fats or mous, the soft or 
indolent ones which, after having eaten a great deal and become 
very fat, die miserably, and enter into a state of putrefaction. 
And. lastly, it is at this age that the muscardine, which hardly 
shows itself at any other age of the insect, appears with great 
intensity. 
The muscardine is a terrible scourge to the rearers of silkworms. 
The losses which result from this disease in France are estimated 
at at least one-sixth of the profits. No particular symptom 
allows of our recognising the existence of this disease in worms 
which, however, contain its germ. Only, the worm, which has 
eaten up to that time as usual, appears almost in a moment to 
change to a duller white; its movements become slower, it 
becomes soft, and is not long before it dies. Seven or eight days 
after its death it becomes reddish and completely rigid. ‘Twenty- 
four hours afterwards a white efflorescence shows itself round the 
head and rings, and soon after the whole body becomes floury. 
This flour is a fungus called Batrytis bassiana, of which the 
mycelium develops itself in the fatty tissue of the caterpillar, 
attacks the intestines, and fructifies on the exterior. This fungus 
has been considered as the immediate cause of the muscardine, and 
has been also regarded as the last symptom or end of the disease. 
The communication of the disease by contagion has alternately 
been admitted and denied. As its true cause, and any efficacious 
means of opposing it, are still unknown, the breeders of silk- 
worms must be content to apply, so as to prevent or struggle 
against this dreadful scourge, the precepts of hygiene: good 
ventilation, excessive cleanliness, frequent délitements, and good 
food properly prepared. 
After the muscardine, we must mention another epidemic disease 
still more terrible: the gattine. This disease shows itself from. 
