affecting the Corn-Crops. 
133 
" This lan a, of a white colour, has six rudimentary feet (fig. 1 ; 
fig. 2, the same magnified) ; its length varying from three to fifteen 
millimetres (viz., from aline to more than half an inch), according 
to its age ; its head, rounded, hemispherical, brown, and like horn, 
is armed with strong mandibles. One finds this larva at the com- 
mencement of June; it is placed in the inside of the stalk, lower 
down and nearer to the earth as it becomes older, and as the ma- 
turity of the plant is more advanced. Finally, some days before 
hanest-time, this larva retreats nearer to the roots of the plant ; it 
constructs, inside of the straw, a silken transparent case (fig. 3 ; 
fig. 4, the same magnified), in which it shuts itself up and passes 
the winter; after, however, having taken the precaution to cut the 
straw circularly on the inside, about twenty-eight or fourteen milli- 
metres from the earth, so that the perfect insect may find no diffi- 
culty in is-suing from its prison. In consequence of this section, the 
straw, having no more sustenance, breaks off at the foot and falls 
to the ground when the wind becomes a little strong ; the field 
then presents the same appearance as if it had been traversed in 
every direction by sportsmen or by animals. 
"A lonff time after harvest, and even during winter, we may 
still find the larvae enclosed in the roots of the stubble; to be satis- 
fied of this, it is only necessary to pull up a number of the pieces of 
straw left adherini; to the roots. Those which contain a larva are 
detached witli the greatest facility, because the straw is sawed cir- 
cularly, as already stated. By looking with attention, one also 
finds at the same period, quite close to the earth, some very short 
pieces of stubble, cut very horizontally, which contain the insect. 
Towards the end of Mav, or when the wheat and rye begin to ear 
and before the flowering, the larvae metamorphose and give birth 
to a fly (fig. 5). These flies distribute themselves over the fields 
sown with wheat or rye, and deposit an egg upon the stem of the 
corn immediately below the ear." 
This group of insects is interesting to the naturalist, as it forms 
the transition from the saw-flies to a family named Siricidee.* 
Like all such insects, it belongs to the order hymenoptera, the 
FAMILY tenthredinid^, and the GENUS CEPHUS of Latreille; and 
the species before us was named sirex pygm.^us by Linnaeus, 
from its being much smaller in size than the other individuals with 
which he associated it. 
1. Cephus pygmmis is of a shining black colour; the head is rather 
large, with prominent eyes, and three minute ocelli on the crown ; 
the antennae are inserted in front of the face; they are tolerably long 
and slender, but slightly clavate and composed of twenty-one joints; 
the basal-joint is ovate, the second minute, six following elon- 
gated, the remainder verj- much shorter, the apex being oval : the 
* Vide Curtis's Brit. ]:nt., fol. and pi. 253 and 460. 
