CH. XII. J THE ICHNEUMON-FLY. 211 



beyond the case which contained it : this, however, 

 I did see — that it gave the whole apparatus move- 

 ments well adapted to make way even in this mor- 

 tar. It turned it half round from right to left, and 

 then back from left to right. I looked on for a full 

 quarter of an hour before the ichneumon had suc- 

 ceeded." 



The following- figures will perhaps serve to give a 

 clearer insight into the manoeuvres of this insect, 

 while driving its ovipositor deeper and deeper. 

 12 3 



The cuts represent an ichneumon fly settled on a wall, in which it 



has discovered the nest of the mason- wasp. 

 In the 1st figure, the ovipositor, or instrument with which the insect 



pierces the cells of the wasp, is seen to be directed under the belly 



of the ichneumon. 

 In the 2d figure, the insect's head being too near the point of the wall 



which is to be pierced, the long ovipositor is obliged to be thrown 



back into a curve ; and, being thus shortened, it is seen to pass 



under the belly of the ichneumon. 

 In the 3d figure, the ovipositor, being still too long, is curved behind 



the insect. It is then passed under its belly, and is seen like a 



thread supported by the right fore-leg of the ichneumon. In order 



to prevent this instrument from bending, while the insect immerses 



it into the mortar, it is obliged to support it with the end of its leg. 



The other two hair-like lines are intended to represent the antennas 



of the insect. 

 The three figures convey a good notion of the great flexibility of the 



ovipositor, and the facility with which the insect can use it under 



any circumstances. 



The manoeuvres of those ichneumons which at- 

 tack the insect itself are as curious. The body of 

 the caterpillar is the matrix destined to receive the 

 eggs of this species.. The little fly maybe seer 



