INSECTA. 
339 
individuals Avhic;h form the greater portion of the community, and by 
whose labour and vigilance the Avhole community are maintained, 
have been considered as being of neither sex. They have also been 
designated by the terms of labourers and mules. It is now known, 
however, that they are females, whose sexual organs or ovaides have 
not been fully developed, and that if an amelioration of their diet 
perfect those organs at a particular ej)och while they are young they 
become fruitful. 
The ova are sometimes hatched in the abdomen of the mother; she 
is \}\QX\viviparous. The number of generations in a year depends on 
the duration of each of them. Most commonly there is but one or 
two. A species, all things being equal, is so much the more com- 
mon, as one generation succeeds more rapidly to another, and as the 
female is more prolific. 
A female Papilio or Butterfly, post coitum, lays her eggs, from 
which are hatched, not Butterflies, but animals with an elongated 
body, divided into rings, and a head furnished with jaws and several 
small eyes, having very short feet, six of which are anterior, scaly, 
and pointed, the rest varying in number and membranous, being 
attached to the posterior annuli. These animals, caterpillars, live in 
this state for a certain period, and repeatedly change their skin. An 
epoch, however, arrives, when from this skin of a caterpillar issues a 
totally different being, of an oblong form and without distinct limbs, 
which soon ceases to move and remains a long time apparently desic- 
cated and dead under the name of a chrijsalis. By close examination 
we may discover on the external surface of this chiysalis, lineaments 
which represent all the parts of the Butterfly, but under proportions 
differing from those they are one day to possess. After a longer or 
shorter period, the skin of the chrysalis splits, and the Butterfly, 
humid and soft, with flabby short Avings, issues from it — a few mo- 
ments, however, and it is dry, the wings enlarge and become firm, 
and the perfect animal is ready for flight. It has six long legs, an- 
tennae, a spiral proboscis, and compound eyes — in a word, it has no 
resemblance whatever to the caterpillar, from which it has originated, 
for it is ascertained that these various changes are nothing more 
than the successive development of parts contained one Avithin the 
other. 
This is Avhat is styled the metamorphosis of Insects. In their first 
condition they are called larvce, in their second pupce or nymphs, and 
in the third perfect insects. It is only in the last state that they are 
capable of reproduction. 
All insects do not pass through these three states. Those Avhich 
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