346 
INSECTA. 
little feet, the second of which, in several, resemble large hooks, that 
appear to replace the four jaws of the last-mentioned animals, or the 
two jaws as well as the lower lip of Insects ; they are a sort of buccal 
feet. The antennae, two in number, are short, somewhat thicker 
towards the extremity, or nearly filiform and composed of seven 
joints in some ; in others they are numerous and setaceous. Their 
visular organs are usually composed of a union of ocelli, and if in 
others they present a cornea with facets, the lenses are still lai’ger, 
rounder, and more distinct, in proportion, than those of the eyes of 
Insects. The stigmata are frequently very small, and their number, 
owing to that of the annuli, is usually greater than in the latter, 
where it never exceeds eighteen or twenty. The number of these 
annuli and that of the feet increases with age, a character which also 
distinguishes the Myriapoda from Insects, the latter ab ovo always 
having the number of segments peculiar to them, and all their legs 
with hooks, or true legs, being developed at once, either at the same 
epoch, or when they pass into their pupa state. M. Savi, professor 
of Mineralogy at Pisa, who has paid particular attention to the luli, 
has observed, that on leaving the egg they are destitute of these 
organs : they experience then a true metamorphosis. In some, the 
male organs of generation are placed immediately after the seventh 
pair of feet, on the sixth or seventh segment of the body, and those 
of the female near the origin of the second feet : in the others the 
two sorts of organs are situated, as usual, at the posterior extremity 
of the body. The position of the male organs of the first compared 
with that in which they are placed in the Crustacea and Arachnides, 
would seem to indicate the separation of the trunk and abdomen : 
with respect to these in which these organs are posterior, we observe 
that an inversion of the successive order of the stigmata takes place 
in an analogous portion of the body of certain species, which appears 
to announce a similar distinction. 
The Myriapoda live and increase in size longer than other Insects, 
and, according to Savi, two years are required to render the genital 
organs of some (the luli) of them apparent. 
From this ensemble of facts, we may conclude, that these animals 
approach the Crustacea and Arachnides on the one hand, and the 
Insects on the other; but that as respects the presence, form and 
direction of the bracheae, they belong to the latter. 
We divide them into two families, perfectly distinct both in their 
organization and habits, and forming two genera according to the 
system of Linnaeus. 
