166 SUPPLEMENT TO THE ORDERS 



them to different bodies. When the season is favourable, these 

 eggs disclose the young at the end of five or six days. On issu- 

 ing from its envelope, the larvae is white and transparent, but 

 when a little more aged it becomes reddish — a fact which 

 might surprise us, did we not know that nature employs so 

 much sagacity and address in her means of preserving the 

 posterity of insects : thus the difficulty we experience in finding 

 this larva in our apartments. No question but that they 

 are very numerous in such places, and yet, if we examine the 

 sweepings of our bed-rooms, with ever so much attention, 

 we rarely succeed in finding a single one. It seems proba- 

 ble that they remain concealed in the folds of such pieces as 

 compose our beds, or in some other place which completely 

 shelters them from our pursuit. It is more easy to find 

 them in the nests of birds, and especially of pigeons. 



These larvae are without feet, though some authors have 

 thought proper to advance the contrary. They look like 

 little worms, and are exceedingly lively after changing into 

 nymphs. Roesel thinks that the individuals which are more 

 clear in colour are the males, but M. Latreille is of a differ- 

 ent opinion, as this difference of tint is not observable in the 

 perfect state, at least as an indication of sex. Eleven or 

 twelve days after this larva has been enveloped in its tomb, 

 the nymph is stripped of a pellicle which enveloped its 

 limbs, becomes the perfect insect, and appears under the 

 form which it is destined always to preserve. It begins to 

 leap at the first moment of its new existence. Those larvae 

 which are born at the close of summer, pass the winter under 

 the same form. 



All the world knows, the fleas are parasitical insects ; 

 they prefer the delicate skin of women and children to that 

 of other persons. They nestle in the fur of hares, dogs, and 

 cats, which are very much tormented by them, especially in 



