DISEASES OF INSECTS. 213 
progress, it is best to burn or bury them, since if the 
poultry pick them up they might be poisoned by them. 
A third disease of silkworms is called Lcs Moris Blancs, 
or Tripes, which is also occasioned by impure air, when 
the leaves the animal feeds upon are heaped so as to 
produce fermentation. The caterpillars attacked by it 
die suddenly, and preserve after their death the sem- 
blance of life and health. Too great heat, whether ar- 
tificial or natural, occasions La Touffe, a fourth, which, 
when the heat continues long, destroys all those that 
are arrived at their last stage of existence in their larva 
state. Black points scattered over different parts of the 
body, or livid and blackish spots in the vicinity of the 
spiracles, followed by a yellowish or reddish tint, are 
symptoms of a fifth malady, called La Muscardine. 
After this the animal soon dies, and becomes mouldy, 
but does not stink. This disease is not contagious, and 
is thought to be caused by a moist heat, attended by 
pernicious exhalations. La Luzette, Luisctte, or Clairene, 
is another malady, which shows itself most commonly 
after the fourth moult. It seems to arise from some 
original defect in the egg. The caterpillars attacked by 
it may be known by their clear red and afterwards dirty 
white colour; their body becomes transparent, and the 
matter of silk exudes in drops from their spinnerets; 
consequently, though as voracious as the rest, they are 
never able to construct a cocoon, and should be de- 
stroyed. Les Dragees is the name given to cocoons 
which include a larva that never becomes a pupa. The 
cause of this disorder has not been ascertained, and whole 
broods are sometimes subject to it, which, as in the last, 
seems to imply some defect in the eggs. But as the ca- 
terpillar spins its cocoon, and the silk is as good as usual, 
