87 
[347] 
whilst he corrected the errors of his predecessors, failed himself 
to detect the radical difference in the nature of the anal sack as 
compared with the larval and medial scales. 
We have thus far spoken only of the female insects and their 
scales, but in addition to these we find upon the leaves about an 
equal number of a much smaller scale, being only one-half as long 
and scarcely half as broad; straight, linear, and cannated.. T is 
is the scale of the male insect. It is found, upon examination, to 
be composed of only two of the corresponding parts oi the female _ 
scale, namely, the larval scale and the anal sack, the medial scale, 
and that stage of growth indicated by it, being absent. Accor - 
indy it attains its growth in a shorter period than that ot the e- 
male, requiring only about ten days for its completion The 
male of this species is deserving of special interest, from t e ac 
that this sex, in the more widely known Bark-louse of the apple 
tree has never been discovered. From the similarity of he two 
species in all their important characters, so far as they are known, 
it is reasonable to assume that the maleot the Aspidiotw (01 as it 
is now called, Mytilaspis) eonchiformis , it it ever be discovered 
will be found to resemble, in all essential characters, the male ot 
the Mytilaspis of the Pine. 
The first sight that I obtained of this interesting insect was on 
the 19th of August, when, upon raising a number ot the small 
linear scales, I detected under one ot them a male individual, m a 
condition analogous to the pupa state, with its rudimental un s 
lying flatly upon its sides, and with a short, obtuse, and but half 
developed style projecting from its anal extremity. On the 23d 
of the same month, I saw a fully developed specimen after it had 
emerged from its cocoon-like scale, and for two weeks following 
Ts, Ly number of them could be obtained by inclosing the mtes- 
ted leaves in a closed bottle. 
It will be borne in mind that the minute larvae of this very 
anomalous tribe of insects, enjoy but a very brief period of active 
We- that they move about over the adjacent leaves and twigs 
fcr i time, rarely ..deeding ». or tbre. d„. 
loave the egg, and then fix themselves immovably. At this inci 
pient stave of their existence the two sexes cannot be distinguished 
from each other. But as soon as they become fixed and begin to 
