IIEMIPTERA. 223 



minute oval dark-colored scales on one of the ends of these 

 white cases are the skins of the lice while they were in the 

 young or larva state, and the white shells are probably formed 

 in the same way aB the down which exudes from the bodies of 

 other bark-lice, but which in these assumes a regular shape, 

 varying according to the sex, and becoming membranous after 

 it is formed. Not having seen these insects in a living state, I 

 have not been able to trace their progress, and must therefore 

 refer to Dalman's memoir above mentioned, for such particu- 

 lars as tend to illusti-ate the remaining history of this species. 

 The body of the female insect, which is covered and concealed 

 by the outer case above described, is minute, of an oval form, 

 A\Tinkled at the sides, flattened above, and of a reddish color. 

 By means of her beak, which is constantly thrust into the 

 bark, she imbibes the sap, by which she is nourished; she un- 

 dergoes no change, and never emerges from her habitation. 

 The male becomes a chrysalis or pupa, and about the middle 

 of July completes its transformations, makes its escape from 

 its case, which it leaves at the hinder extremity, and the wings 

 with which it is provided are reversed over its head during the 

 operation, and are the last to be extricated. The perfect male 

 is nearly as minute as a point, but a powerful magnifier shows 

 its body to be divided into segments, and endued with all the 

 important parts and functions of a living animal. To the 

 unassisted eye, says Dalman, it appears only as a red atom, 

 but it is furnished with a pair of long whitish wings, long 

 antennae or horns, six legs with their respective joints, and two 

 bristles terminating the tail. This minute insect perforates 

 the middle of the case covering the female, and thus celebrates 

 its nuptials with its invisible partner. The latter subsequently 

 deposits her eggs and dies. In due time the young are hatched 

 and leave the case, under which they were fostered, by a little 

 crevice at its hinder part. These young lice, which I have 

 seen, are very small, of a pale yellowish brown color, and of 

 an oval shape, very flat, and appearing like minute scales. 

 They move about for a while, at length become stationary, 

 increase in size, and in due time the whitish shells are pro- 

 duced, and the included insects pass from the larva to the 



