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 larger, 

 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. 



