LEPIDOPTERA. 235 
When they have awoke 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 /uzsettes, 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 //ats 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 muscadine, which hardly 
shows itself at any other age of the insect, appears with great 
intensity. 
The muscadine 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 Botrytis 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 
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considered as the immediate cause of the muscadine, 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 muscadine, we must mention another epidemic disease 
still more terrible : the gattine. This disease shows itself from the 

