146 THE ENTOMOLOGIST. 



larva of Acronycta, and placed it in a box, where it spun up. 

 On removing the cover I ruptured the silken cocoon, and 

 discovered that the larva was about to change into a pupa. 

 I was surprised to see that with the skin it was also throwing 

 off six small hjmenopterous larvae, which spun their cocoons 

 in the cast-off skin. The lepidopterous larva changed to a 

 pupa, which has since dried up. This convinced me that 

 the parasitic puyjaj found in the cocoons had been thrown 

 off in a similar manner, as none of the pupge showed the 

 slightest trace of punctures through which the larvae could 

 have escaped. May not this arise from the eggs of the 

 ichneumon having been deposited in the larvae during the 

 later stages of their growth ? They would then be ready to 

 enter the pupa slate before the parasitic larvae had attacked 

 the vital parts. These, feeding directly under the skin, 

 would be thi-own off with it. Are not the whole of the so- 

 called changes of skin (except the last) merely a throwing ofi' 

 of the epidermis, the last a casting of the entire skin ? If 

 not, why were the larvae thrown off in the last and not with 

 the previous changes ? I think, if this were to be properly 

 investigated, Entomologists would soon be able to account 

 for the not infrequent occurrence of a lepidopterous and hy- 

 menopterous imago from one cocoon. — Henry Moncreajf. 



76. Crickets and Cockroaches. — My present residence, an 

 old country house, was neither infested with cockroaches nor 

 crickets until very lately. The cockroaches made their ap- 

 pearance about four years ago, and increased so rapidly and 

 to such an extent that every night the kitchen-floor was 

 black with them when the candle had been out about an 

 hour. They made their way into every place, and although 

 we tried every means to kill them they seemed to increase 

 the faster, as if in mockery of our efforts. During last winter 

 the chirp of the cricket was heard by the fire-side, and they 

 increased from the solitary one to a full and noisy chorus, 

 and as they increased the cockroaches decreased, and now 

 (August) there is not a cockroach to be found. It has long 

 been one of the articles of *' folk-lore " that the two will not 

 live together, and here is a proof A neighbour of mine, a 

 large farmer, has lost the crickets and is pestered with the 

 cockroaches, whicli live and increase in spile of shoe-heel, 



