


226 THE INSECT WORLD. 
held up by the silken threads. The duration of the time occupied in 
moulting varies with the degree of the heat or humidity of the 
atmosphere ; but in general the state of sleep lasts from twelve 
to twenty-four hours. One hour after the crisis the worm begins 
again to eat. 
Tne ages of the silkworm are the periods of time which elapse 
between one moult and another. If one observes some silk- 
worms when the temperature is favourable, we shall find that 
there are four moults, and consequently five ages. At the first 
age (Fig. 204), the silkworm is black and hairy ; then of a nut 
colour at the moment when the first moult 1s going to 
om ° take place. ‘The appearance presented by these worms 
gue collected together on a leaf,” says Dandolo, “ is that of a 
Sa downy surface of a dark chestnut colour, in the midst of 
frst age. which one sees nothing but a movement of little animals 
having their heads raised, working them about, and presenting 
black, shiny muzzles. Their bodies are completely covered with 
hairs arranged in straight lines, between which one perceives 
along the whole length of the body other longer hairs.”’* 

Yarra 

Fig. 205. Fig. 206. Fig. 207. 
Second age. Third age. Fourth age. 
The first age lasts for five days. At the second (Fig. 205), the 
worm is grey, almost without down, then of a yellowish white, 
and one sees the crescents making their appearance on the second 
and fifth segment. At the third age (Fig. 206), there is nota 
single hair remaining, and the worm becomes whitish, and 1: 
always becoming lighter. The third age lasts six days, as does 
also the fourth (Fig. 207). At the fifth (Fig. 208), the worm 
has very nearly reached the end of its career in the caterpilla 
state, and now is the time of its greatest yoracity. This age i 
the longest ; it lasts nine days. | 
* “Art d’élever les Vers a soie, par le Comte Dandolo.” In 8vo. 2e édition 
Lyon, 1825. 
