350 Mr. A. Murray on the History 



wasp's larva, easily recognizable by its mandibles. At first 

 sight this might seem to indicate that the Rhiptjyhorus had 

 consumed a previous tenant of the cell, and recalled to my 

 mind the way in which Mr. Stone speaks of his wasp-larva being 

 devoured by a E/njjqyhorus-lnYva, except " skin and mandi- 

 bles," in forty-eight hours. But if any one will search the 

 cells of the wasp-pupa3, and still more those of the hornet, 

 they will constantly find the same thing, a shred of skin and 

 mandibles, the skin of the mandibles being particularly notice- 

 able in consequence of its greater strength, higher colour, and 

 definite form. It is plainly the cast skin of the larva. It has 

 all the look of a cast skin (every entomologist will recognize 

 my meaning) ; and its occurrence in cells inhabited by Bkipi- 

 phorus is simply due to the ItJiipiphorus having taken up its 

 abode in a cell formerly inhabitecl by a wasp-pupa. Mr. Stone's 

 observation, as it appears to me, must rest on a mistake in 

 some way arising out of such a cast skin. The wasps, indeed, 

 are said to clear out the cells Avhich have been inhabited pre- 

 viously, before laying their eggs in them again. I have seen 

 no indication of any such cleaning or redding up for a ncAV 

 tenant. The d^gats at the bottom are left all standing, and, 

 from the size of this dung-heap (especially in the hornets' 

 cells, where the quantity is naturally much greater), it is not 

 difficult to distinguish those cells which have had more than 

 one tenant from those which have been used only once. The 

 silvery lining of the walls is all left, and, what we have spe- 

 cially to do with also, the cast skin of the previous larva. It 

 is constantly to be seen in the cells ; and that we do not see it 

 always may be due to its sometimes decaying away or getting 

 covered with additional rejectamenta ; for it is plain that the 

 digestive operations will continue after the insect has ceased 

 to feed, and shut itself up, until the contents of its stomach 

 are all voided. This, moreover, is proved by the black deposit 

 having been found at the mouth of the cell in the case of the 

 reversed specimen first above noticed. If it had been depo- 

 sited prior to sealing up, it must have fallen out, not to s])eak 

 of the barrier it would be to the larva in spinning itself up. 

 The eggs of the wasps are not deposited, as by the bees, at 

 the bottom of the cell, but about a third of the way up, so that 

 this debris does not interfere with them. 



In picking out some specimens of cells with eggs attached, 

 Miss Eleanor Ormerod observed some with two eggs in the 

 same cell. She sent me some of these combs, in which a 

 tolerably large proportion (about four out of a score) had 

 two eggs, either both in the state of eggs, or a yoinig hirva 

 at the bottom and an q^^ not yet hatched adhering to the 



