740 
| Assemble 
Under these scales I have also repeatedly met with a small 
maggot, three hundredths of an inch long, or frequently much 
smaller, of a broad oval form, rounded at one end and tapering 
to an acute point at the other, soft, of a honey-yellow color, 
slightly translucent and shining, with an opake brownish cloud 
in the middle, produced by alimentary matter in the viscera, and 
divided into segments by faintly impressed transverse lines. This 
is probably the larva of some minute Hymenopterous insect, spe 
cially designed by Providence for destroying the eggs of the bark 
louse. That these eggs are its food is shown by the fact that 
when the maggot is small a number of eggs are found under the 
scale with it, when it is larger the eggs are fewer. The indivi¬ 
dual from which the above measurement and description was 
drawn had but two eggs remaining for it to consume. Whether 
the maggot be larger or smaller it, with the eggs, appears to com¬ 
pletely fill the cavity beneath the scale, and I have only met 
with this parasite upon thrifty trees, where each scale had a large 
number of eggs beneath it. It doubtless remains beneath the 
scale during its pupa state, and then makes its exit by perforating 
a small round hole through the scale. Scales which are thus 
perforated may frequently be met with. Ou*' cut represents a 
scale magnified and perforated for the escape of a parasite, the 
short line on the right hand side of the figure indicating the natu¬ 
ral length of the scale. 
The eggs are somewhat less than the hundredth part of an inch 
in length ; they are of a regular oval shape, about twice as long 
as broad, smooth but not shining, opake, most of them of a white 
color, others dull pale yellow. , 
As early as the 12th of May I have found individual larvse 
hatched, and running about with much activity among the eggs, 
but remaining under the scale for protection. It is not till about 
a fortnight later that the eggs mostly become hatched, and the 
young crawl out from under the scale and scatter themselves over 
the bark. To the naked eye they appear like minute white dots, 
uniformly diffused over the smooth bark of the twigs, and ap¬ 
pearing like natural white points or glands of the bark. A per¬ 
son to whom I once pointed out these white specks was reluctant 
