394 Mr. F. Smith on the Parasitism 



even after they have passed into the pupa state. They scarcely 

 appear to cease eating, except now and then for a minute or 

 so, from the time they first begin to feed till they have become 

 full-grown." 



Thus we learn that Mr. Stone's observation was not confined 

 to that of the single larva " attached to the full-grown larva 

 of the wasp ; " on the contrary, from subsequent observations, 

 he was enabled to ascertain that these creatures, in the pupa- 

 state, retain in their grasp the skin of their victims. 



Again, he says, " I took out thirteen more nests of V. vul- 

 garis, which contained examples of Bhipijyhorus, either in the 

 larva-, pupa-, or perfect state. In one that had been destroyed 

 by means of gas-tar a few days before, I was fortunate in dis- 

 covering a small larva of RMpijjliorus firmly attached to its 

 victim : both were dead, and had become partially dried ; so 

 that when immersed in spirits they did not separate, but re- 

 mained attached just as they were before death. 



" Another nest was taken out on the 2nd of September ; and 

 on a closed cell being opened, that was appropriated to a 

 queen, a larva of Rhipiphorus was discovered ; an adjoining 

 cell contained a pupa ; both these were about double the size 

 of larvas and pupas found in cells of worker wasj)s." 



Shortly after the publication of Mr. Stone's paper in the 

 ' Zoologist,' vol. xxiii. (1865), that gentleman presented to 

 me the whole of the collection he had made of larvge and pupas 

 alluded to in his paper. I have before me a small phial con- 

 taining the larva of the wasp that has that of its destroyer 

 firmly attached to it, as mentioned above ; I have also a phial 

 that contains a number of pupas extracted from worker-cells, 

 together with one extracted from a queen's cell, showing how 

 greatly these parasites diiFer in size ; then I have larvse of 

 wasps only partially devoured, together with undergrown larvie 

 of Rhipiphorus. To myself such evidence is conclusive ; 

 and it only remains necessary that I examine how far Mr. 

 Murray's discoveries are reconcilable with the apparently 

 proved habit of the parasitism of Rhipiphorus as discovered 

 by Mr. Stone. 



Mr. Murray informs us that Miss Ormerod observed some 

 cells with two eggs in each (about four in a score had two 

 eggs) ; in others a young larva at the bottom, and an tg^ not 

 yet hatched adhering to the cell higher up. Mr. Murray in 

 these cases regards one of the eggs as that of Rhipiphorus ; 

 this is exactly what I should conclude would be the case ; the 

 e^g of the parasite, since it feeds upon the full-grown larva of 

 the wasp, after the latter has spun the silken covering to the 

 cell, would remain undeveloped until the wasp-larva was full- 



