Clifton College Scientific Society. 9 



they deposit eggs in the bodies of their victims, which eggs 

 develope into parasitical larvce. This department of ento- 

 mology is well worth studying, as it opens up facts of the 

 highest interest. You can scarcely collect a series of cocoons 

 without finding some parasite in attendance on the inmates. 

 About a month ago I gathered two or three heads of the 

 common yellow toad flax (Linaria vulgaris), the seed vessels 

 of which were evidently infested with some insect. I placed 

 the heads under a tumbler, with a glass over it. (I may 

 mention en passant, that this forms a convenient ' breeding 

 cage ' for small objects, as every movement and every 

 change of the little prisoners can of course be watched with 

 the greatest ease ; moreover, if the bottom of the tumbler be 

 lined with an inch or two of damp earth, the ends of the 

 leaves or twig on which the animals feed can be inserted, 

 and thus kept alive and fresh for a long period, the cover 

 preventing evaporation.) 



In a few days I saw numbers of a small, dark-coloured 

 rhyncophorous beetle wandermg over the sides of the tumbler, 

 which I was able to identify as Gymnetron (or Bhinusa) antir- 

 rhini ; but, besides the beetles, there were at least as many 

 specimens of a tiny hymenopterous insect (I believe, an 

 Alysia), with most delicate legs and antennae, and with wings 

 which, under the concentrated light of the microscoj^e, 

 glittered with the lustre of the most gorgeous jewels. Nearly 

 the same circumstances occurred on watching a head of 

 stinging nettle, and another of the common furze, each of 

 which was crowded with dark-coloured J.jj/iwZes. In this case, 

 however, the robber ichneumon fly issued from the adult 

 Aphis, instead of from the helpless pupa. A curious sight, 

 by the way, is an Aphis after its destroyer has made its 

 escape. The little animal appears to have been quite un- 

 conscious of the enemy's presence, and to have sucked at the 

 plant before it up to the last moment of its sluggish exist- 

 ence. Its rostrum is still fixed in the rind; its legs are 

 planted in their natural position, as firmly as ever ; save that 

 the body has assumed a light brown hue, the casual observer 

 would see no difference. But, for aU that, life has gone; the 

 animal is a mere hollow shell, and a small round* orifice in 

 the back marks the spot whence the intruder has crawled 

 forth after it has done its dea,dly work. 



But parasites do not always, as in the foregoing case, lay 

 a solitary (^.gg in their prey. Two or three larvae of the 

 common cabbage butterfly {Pontia brassica?), which I collected 

 this year, gave birth each to forty or fifty tiny parasites, 



