this number in our species is that we have not happened to see 
them all separated. The length of this proboscis is also difficult 
to be ascertained, on account of its fragility, and the consequent 
doubt, in any case, whether we have extracted the whole ot it 
from the bark. In my experience it has usually broken off, either 
close to the body, or of a length somewhat less than that of the 
body, though I have seen it considerably longer. M. Signoret 
says that in some species he has seen it twice the length of the in¬ 
sect’s body, and in rare instances even three times as long. I 
once removed a young female of the pine leaf species (Mytilaspis 
pintfolice, Fitch) just as it was beginning to form the terminal 
shield, and when it was scarcely one-thirtieth of an inch long, in 
which the proboscis was two lines, or one-sixth of an inch in 
length, by actual measurement, and therefore fully five times the 
length of the insect’s body. In this instance I noticed that the 
proboscis was filiform, or of equal thickness for the greater part 
of its length, and that it thence tapered to a very fine point, from 
which I concluded that I had succeeded in extracting the whole of 
the instrument from the leaf. 
It is difficult to conceive how so delicate and fragile an organ 
can be inserted into the leaf, and much more into the tough tissue 
of the bark. I once succeeded in tracing the proboscis of the 
Pine-louse, for about half its length, running horizontally, just un¬ 
der the semi-transparent cuticle, and it is not improbable that this 
is the situation in which the instrument is usually introduced. 
Notwithstanding the sluggish and apparently almost lifeless con¬ 
dition of the female Coccus , the proboscis seems to be endowed 
with a special vitality. I have often seen it move with a waving 
or serpentine motion, and M. Signoret thinks it is capable of a 
considerable degree ot extension and retraction, and it was some 
action of the attached proboscis, no doubt, which produced the 
jerking motion of the insect’s body noticed by Dr. Shimer. 
Upon the interesting topics of the difference of the sexes in 
this tribe of insects, and the nature and growth of the scale by 
which they are protected, we have made a somewhat systematic 
series of observations during the past season, but we have prefer¬ 
red to avail ourselves, for this purpose, of the species which dwells 
on the pine-leaf, for the reason that the existence and characters 
of the male of this species are known, and that the several parts 
