REPORT OF THE ENTOMOLOGIST. 219 
It has in fact become a true domesticated animal. The quality which 
man has endeavored to select in breeding this insect is, of course, that of 
silk-producing, and hence we find that, when we compare it with its wild 
relations, the cocoon is vastly disproportionate to the size of the worm 
which makes it. or the moth that issues from it. Other peculiarities 
have incidentally appeared, and the great number of varieties or races 
of the silk-worm almost equals those of the domestic dog. The white 
color of the species, its seeming want of all desire to escape as long as 
it is kept supplied with leaves, and the loss of the power of flight on thd 
part of the moth, are all undoubtedly the result of domestication. From 
these facts, and partienlarly from that of the great variation within spe- 
cific limits to which the insect is subject, it will be evident to all that the 
following remarks upon the nature of the silk-worm must necessarily be 
very general in their character. 
The silk-worm exists in four states—egg, larva, chrysalis, and adult 
or imago—which we will briefly describe. 
DIFFERENT STATES OR STAGES OF THE SILK-WORM. 
THE EGG.—The egg of the silk-worm moth is called by silk-raisers the 
“seed.” It is nearly round, slightly flattened, and in size resembles a 
turnip-seed. Its color when first deposited is yellow, and this color it, 
retains if unimpregnated. If impregnated, however, it soon acquires a 
gray, slate, lilac, violet or even dark green hue, according to variety or 
breed. It also becomes indented. When diseased it assumes a still 
darker and dull tint. With some varieties it is fastened to the substance 
upon which it is deposited by a gummy secretion of the moth produced 
in the act of ovipositing. Other varieties, however, among which may 
be mentioned the Adrianople whites and the yellows from Nouka, in the 
Caucasus, have not this natural gum. <As the hatching point approaches, 
the egg becomes lighter in color, which is due to the fact that its fluid 
contents become concentrated, as it were, into the central, forming worm, 
leaving an intervening space between it and the shell, which is semi- 
transparent. Just before hatching, the worm within becoming more 
active, a slight clicking sound is frequently heard, which sound is, how- 
ever, common to the eggs of many other insects. After the worm has 
made its exit by gnawing a hole through one side of the shell, this last 
becomes quite white. Each female produces on an average from three 
to four hundred eggs, and one ounce of eggs contains about 40,000 in- 
dividuals. It has been noticed that the color of the albuminous fluid of 
the egg corresponds to that of the cocoon, so that when the fluid is white 
the cocoon produced is also white, and when yellow the cocoon again 
corresponds. 
THE LARVA oR Worm (P1.I, Fig. 1).—The worm goes through from 
three to four molts or sicknesses, the latter being the normal number. 
The periods between these different molts are called “ages,” there being 
five of these ages including the first from the hatching and the last from 
the fourth molt to the spinning period. The time between each of these 
molts is usually divided as fellows: The first period occupies from five 
to six days, the second but four or five, the third about five, the fourth 
from five to six, and the fifth from eight to ten. These periods are not 
exact, but simply proportionate. The time from the Hatching to the 
spinning of the cocoons may, and does, vary all the way from thirty to 
forty days, depending upon the race ‘of the worm, the quality of the 
food, mode of feeding, temperature, &c.; but the same relative propor- 
tion of time between molts usually holds true. 
