348 ON THE ORDERS 



occurs to our recollection. These last are herbivorous 

 animals, or at least feed on organized matter in a state of 

 decomposition, like the Crustaceous genera Armadillo and 

 Porcellio. They differ from them in breathing by stig- 

 mata, and having in general two pair of feet for certain 

 segments of their body. It is to be remarked, however, 

 that while these insects have a tracheal system of respi- 

 ration, their stigmata, as might be expected when we 

 consider that the mode of breathing has just been changed, 

 are often very minute, and sometimes, as in the genus 

 Glornerisy almost imperceptible. 



Havincf thus established a connexion between Porcellio 

 and lulus, I would next observe, that in the Mtmoires de 

 V Academic des Sciences M. Degeer acquainted naturalists 

 with the fact, that on quitting the egg the young luli are 

 quite different in appearance from what they are in the 

 adult state ; having at first only six feet, and these disposed 

 in one pair for each of the three first annuli of the body. 

 He observed that in this their young state the segments 

 of the body were never more in number than seven or 

 eight, but that by a sort of metamorphosis, no less sur- 

 prising to him than that of winged insects which have a 

 pupa state, die number of segments and of feet increased 

 with the age of the Inlus. This singular discovery is of 

 such importance to Entomology that I shall be excused for 

 transcribing the words of Degeer himself. 



Having procured some eggs of lulus terrestris Linn, 

 whicli the warmth of a few summer days soon hatched, he 

 perceived a small white larva to proceed from each. " Ces 

 jeuues lules," he says, " nouvellemeut eclos me firerit voir 

 une chose a laquelleje ve m'atleudois nullemeut . Je sa- 

 tois que tes inseptes de ce genre ne suhissent point de mtta- 



