152 INTERNAL ANATOMY OF INSECTS. 
ceps, and hollowed above into a channel for the passage 
of the eggs?. 
In the Orthoptera the instrument of oviposition is more 
simple ; in Locusta Leach, consisting merely of four ro- 
bust three-sided pieces, two above and two below, the 
former pair at the end curving upwards and the latter 
downwards®, these pieces seem calculated when they 
have entered the earth to enlarge the burrow, and the 
animal appears able to separate them very widely from 
each other®. The ovipositor of Acrida viridissima, which 
like that of many Hymenopterous insects forms a kind 
of appendage or tail to the body, has been described 
both by De Geer and Latreille as consisting of two valves 
only?; but in reality it consists of s?z, two upper and four 
lower, as you may ascertain by means of a pin or the 
point of a penknife, which will readily separate them. 
This is confirmed by a figure of Stoll’s of a species which 
seems to connect Conocephalus Thunb. with Gryllus 
Latr. In this the ovipositor is considerably longer than 
the body of the animal, and is composed of séx distinct 
pieces ; viz. two external ones stouter than the rest, and 
within these four others finer than a hair and convolute 
at the apex*. There is a considerable variety in the 
shape of the ovipositors of the Acrid@ and the cognate 
genera :—thus in A. viridissima this organ is straight, in 
A. verrucivora bent like a sabre, and in Pterophylla citri- 
folia K. and some others, the whole machine is short 
and boat-shaped ; in Scaphura Vigorsii K. it is also rough 
with sharp little tubercles‘. I had an opportunity of 
* De Geer v. 62. ¢. iii. f. 12. > Pirate XV. Fic. 18. 
* Stoll Sauterel. t. xxii. b. f. 87, &c. * De Geer iii. 418. 7. xxi. 
f. 10, 11. Latr. Gen. Crust. et Ins. iii. 98. 
* Stoll ubi supr. ¢. xili, a. f. 51. * This insect, which con- 
