37 
cious appetite, one would still think the worms in perfect health, for 
they yet retain all the outward perfection of form that we have re- 
marked above (Plate I, ig. G). In color they have, perhaps, become 
somewhat more rosy, especially if the disease is in a violent form. On 
touching them, however, we find them soft, and even in this seemingly 
live condition they are often dead. Had the worms been carefully ob- 
served at this time, it would have been seen that the beating of the 
dorsal vessel was gradually becoming slower, and thatit finally stopped 
altogether. A green drop appears at the mouth and the worm secretes 
a dirty liquid, which soils the anal orifice and gradually closes it. 
Before many hours are passed the skin begins to shrivel and draw in 
around the fourth and fifth joints of the body, viz: those two lying be- 
tween the set bearing the legs 
proper and the set bearing the 
prolegs (Plate I, Fig. F). Later, 
at this restricted point, the body 
begins to turn brown (Plate I, 
Fig. E), then black, and the whole 
worm is soon in an advanced state 
of putrefaction. Then, and even 
before the death of the worm, a 
sour odor is perceptible in the 
magnanerie, due to the fatty vol- 
atile acids exuded by the victims 
to the disease. Should the malady |i 
strike the insects at a later period, \\ 
when they are ready to spin their 
cocoons, the same languishing air 
will be observed; they will show a 
reluctance to crawl up into the 
arches, and will be seen to gather 
around their bases, seeking some 
place which it requires no exertion 
to attain to spin their cocoons. 
Many of those which reach the 
branches stretch themselves out i | 
motionless on the twigs and die hh | 
there. They are to be seen later wil, { | 
hanging by their prolegs in differ e < § 
ent states of putrefaction (Fig. 22): Fig. 22.—Silk-worms at the spinning period, after 
When these symptoms are ob- death by flaccidity (after Pasteur). 
served we may be sure that the worms are attacked by ftlaceidity 
(flacherie). 
Internal symptoms.—A microscopic examination of the intestines of 
the sick worm will show masses of undigested food, and the coats of the 
intestines will be found to be opaque. Here, too, the microscope re- 
