THE LARCH WORM. 885 
The eggs had all hatched by June 23 to 28 ; few were to be found at 
Brunswick, although the incisions made by the female were commonly 
observed. The female saw-fly makes about a dozen incisions in the ter- 
minal young, fresh, green shoot, sometimes in one of the side shoots 
next to the terminal one; judging by the shape of the hole, the eggs 
are of the shape described by Eatzeburg, i. e., oval cylindrical and 
about 1.5 mm iu length. The eggs are placed in two rows, alternating, 
not exactly parallel, one being placed a little in advance of the other. 
The eggs are inserted at the base of the fresh, soft, young, partly-devel- 
oped leaves of the new shoot, which is usually by June 20-30, only 
about an inch or an inch and a half in length. The presence of the 
eggs causes a deformation of the shoot, which curls over, the incisions 
being in all cases observed on one (the inner) side of the shoot. In 
many cases a last year's shoot was observed with the scars of the 
incisions on the concavity of the shoot. That the incisions were made 
by the saw-fly was proved by finding a freshly hatched but dead larva 
in one of the holes. Sometimes one or two of the leaves die in conse- 
quence of the wounds made at their base. 
After the foregoing lines were written we fortunately observed a 
female in confinement, June 29", while engaged in the process of oviposit- 
ing ; we should judge that the operation of sawing the slit and depositing 
the egg required not less than five minutes, and perhaps not much more 
than that length of time. The fly had been evidently at work for some 
time previous, as a number of eggs had been laid along the shoot ; she 
had begun at the farther end and worked down to the base of the new, 
fresh, green shoot. She stood head downward while engaged in making 
the puncture, and was not disturbed by our removing the larch twig 
from the glass jar and holding it in our hand while watching the move- 
ments of the ovipositor under a Tolles triplet. The two sets of serrated 
blades of the ovipositor were thrust obliquely into the shoot by a saw- 
ing movement ; the lower set of blades was most active, sliding in and 
out alternately, the general motion being like that of a hand saw. After 
the incision is sufficiently deep, the egg evidently passes through the 
inner blades of the ovipositor, forced out of the oviduct by an evident 
expulsive movement of the muscles at the base of the ovipositor. The 
slit or opening of the incision after the egg has passed into it is quite 
narrow and about lf' T,m iu length. While engaged in the process the 
.antennae are motionless, but immediately after the ovipositor is with- 
drawn they begin to vibrate actively, the insect being then in search 
of a site for a fresh incision. 
After making the foregoing observations we found at Phillips, Me., 
July 1, and Errol, N. H., July 4, numerous twigs containing eggs, and 
the flies were also observed upon the trees ovipositing. Although the 
slit is at first closed, as soon as the embryo increases in size the twigs 
swell where they have been incised by the ovipositor, and the slits en- 
large and gape more or less, becoming much larger and more conspicuous 
