6910 Insects. 



lepidopterous larvae. Which of these two courses is pursued by thera 

 remains to be discovered. Their hours for emerging seem to be 

 restricted to a certain portion of each day ; for during the time I was 

 almost exclusively engaged in making observations upon thera, a 

 period extending over five days, none made their appearance before 

 about ten o'clock in the morning, nor after about four in the after- 

 noon ; while between those hours a considerable number were pro- 

 duced each day. 



The specimens, sixty in number, obtained on the first and following 

 day, were placed with all possible care — as soon as they had left the 

 nest, and with a sort of flying leap had alighted on the window — in a 

 gauze bag, in which they were confined for a time. From the bag 

 they were carefully removed, and placed in a bottle containing 

 bruised laurel-leaves, and from the bottle transferred to a tin box, in 

 which they were secui'ely packed and sent to Mr. Douglas. They 

 reached their destination in perfect safety ; but, upon examination, 

 nearly one-third of the whole number, and those, with two or three 

 exceptions, females, were found to have a deficiency in the proper 

 number of legs ; and although diligent search for the missing articles 

 was made, both in the window, the bag and the bottle, no trace of 

 them could be discovered. If therefore they brought the full comple- 

 ment of legs into the world with thera, how is their disappearance 

 to be accounted for ? 



Neither on their first emerging, nor during the period of their con- 

 finement in the bag, did the sexes take the least notice of each other, 

 ihus following the example of the inhabitants of the nest among whom 

 they had been brought up. In the case of both these insects it seems 

 absolutely necessary that the air of heaven should fan their love into 

 a flame before it will burn, since, so far as I have been able to observe, 

 copulation never takes place, either among wasps or their parasites, 

 till they have taken their flight from the nest, never more to return to 

 it. In this respect the habits of Ripiphorus contrast strongly with 

 those of Sitaris; the cause of which becomes apparent on comparing 

 the history of the two insects upon which they are parasitic, instinct 

 teaching the latter-named parasites that they may safely deposit their 

 eggs at once, and in the very -spot in which they have themselves 

 been reared ; for that the bee of the following year will not fail to 

 construct her cells upon the self-same spot, — a spot which has been 

 the birth-place of the species for ages past, and which will in all pro- 

 bability continue to be so for ages to come ; while it points out to the 

 former that they cannot deposit theirs, with any possible chance of 



