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Proceedings of the Royal Society of Edinburgh. [Sess. 
had cleared and inserted her ovipositor, first raising over her back its two 
outer sheaths. She remained thus for nearly seven minutes, when she 
again turned and renewed her excavation, and once more turned round and 
inserted her ovipositor. After a short time she crawled away. 
During all her digging she exposed only a small portion of her prey, 
and on examining it in the afternoon eleven eggs had been deposited, 
all of them on the hard chi tin of the dorsal surface of the prothorax. 
In all the grubs examined this part of the body has invariably been 
selected by the Bracon for her eggs. Naturally, they are sometimes 
displaced by the wriggling of the host, but never to any extent. 
In a previous paper I stated that the weevil grubs were attacked only 
in their resting stage. This has not been confirmed in the laboratory, both 
half and full-grown grubs being deposited on. 
The act of oviposition causes no inconvenience or discomfort to the 
weevil grub. Its skin is not in any way injured, and indeed the female 
Bracon selects a strongly chitinised portion of her prey’s body, and so 
eliminates most of the risk of disturbance which the act of oviposition 
might cause. (Plate II, fig. 13.) 
The number of eggs deposited by the Bracon on a single grub varies 
considerably. In some cases it is as few as eight ; in others I have counted 
twenty-two ; the average was seventeen. The eggs are laid in clusters. 
The Egg. 
The egg of the Bracon is long and spindle-shaped. Its external surface 
is white, glistening, and unsculptured. The micropyle is not distinguish- 
able. The egg measures ‘9 mm. in length and T5 mm. in diameter at the 
middle. (Plate I, fig. 3.) 
Hatching. 
Examination of the empty egg-shells shows that on hatching the egg 
splits along its dorsal surface. Hatching takes place two to four days 
after oviposition. 
The First-Stage Larva. 
The first-stage larva of this Bracon is a tiny grub *8 mm. in length. It 
is legless, and only two regions are recognisable, viz. head and tail. This 
tail, comprising the thoracic and abdominal regions, consists of thirteen 
segments, which are well defined. Each segment bears a row of tiny bristles 
over its whole surface. The first segment is the largest, and the rest 
become smaller in succession. The head is well defined, and bears a pair of 
simple (unjointed) horn-like antennae. The mouth parts are most difficult to 
distinguish, but they consist of a pair of minute, sharp-hooked mandibles, 
