THE ROSE SAW-FLY. 
525 
and connection, Avlncli in particular cases if we fail to dis¬ 
cover, it is rather to be attributed to our own ignorance and 
short-sightedness than to any want of harmony and regu¬ 
larity in the plan of the Creator. In considering the resem¬ 
blances of species, we cannot fail to admire the care that 
has been taken, by almost insensible shades of difference 
among them, or by peculiar circumstances controlling their 
distribution, their habits of life, and their choice of food, 
to prevent them from commingling, whereby each species 
is made to preserve forever its individual identity. 
The saw-flv of the rose, which, as it does not seem to 
have been described before, may be 
called Selandria Rosce (Fig. 245), from 
its faA'orite plant, so nearly resembles 
the slug-worm saw-fly as not to be 
distinguished therefrom except by a 
practised observer. It is also very 
much like Selandria harda^ and 'pygmcea^ but has not 
the red thorax of these three closely allied species. It is 
of a deep and shining black color. The first two pairs 
of legs are brownish-gray or dirty white, except the thighs, 
which are almost entirely black. The hind legs are black, 
with whitish knees. The wings are smoky, and transparent, 
with dark brown veins, and a brown spot near the middle 
of the edge of the first pair. The body of the male is a 
little more than three twentieths of an inch lono;, that of 
the female one fifth of an inch or more, and the wino;s 
expand nearly or quite two fifths of an inch. These saw- 
flies come out of the ground, at various times, between 
the 20th of Mav and the middle of June, durino; which 
period they pair and lay their eggs. The females do not 
flv much, and mav be seen, durino; most of the dav, restino; 
on the leaves, and, when touched, they draw up their legs, 
and fall to the ground. The males are more active, fly 
from one rose-bush to another, and hover around their 
sluggish partners. The latter, when about to lay their 
Fig. 245. 
