194 Dr. T. A. Chapman on the Parasitism 



of Rhipiphorns to be reared in precisely the same way as 

 tliose of the Avasp, is the silken coveriiii; always found over 

 the pupa of RhipijyJionts, just as over that of the wasp, I 

 have never seen any difference between the silk covering a 

 Bhijyiphonts and that covering a wasp, thougli I have found 

 it possible to guess the cell containing the beetle by the 

 shining-through of the differently coloured inmate. It seems 

 very probable, from what we know of the mimicry by guest- 

 insects of their hosts, that its silk would closely resemble that 

 of the wasp, did it spin silk at all. The only instances of 

 beetles spinning any thing like silk, that I can call to mind, 

 are Cionus and its allies, and the doubtful instances of Cocci- 

 nelhi and Donacia. 



In discussing the difiiculties raised by Mr. ^lurray in the 

 way of Mr. Smith's view of the economy of R/iipi/)honis, I 

 shall dismiss his objections to the supposition of the /?///)>/- 

 jy/iorus-larxa devouring several wasp-larvfe, because I have no 

 wish to defend such a theory, nor do I suppose that ^Ir. Smith 

 has. But the objections he raises to the h}"pothesis of its 

 devom'ing only one larva, viz, the one in whose cell the egg 

 of Bhipiphorus is laid when the larva has done feeding, and 

 is spinning or about to spin, all appear to me to be invalid. 

 He first asks ^Ir. Smith if a meal of one animal can suffice to 

 nourish another into as great dimensions as the animal eaten, 

 Mr. Murray here stretches his point a little. The Bhipiphorits 

 is not of as great dimensions as the animal eaten, although it 

 is ver)' nearly so. It is little if at all nearer to the dimensions 

 of the Avasp than Chrysis hideniata is to the dimensions of its 

 host Odi/nerus spinip)es^ of which I have sufficiently proved it 

 eats but one larva. ( )r I might put this in a still stronger 

 form: Chrysis negJecta^ differently from ('. bidentafa, eats not 

 the wasp-larva, but the .store of pabulum laid up for the larva 

 of the Odynerus. It might certainly, then, so far as store of 

 nutriment goes, be as large as the wasp ; yet it is smaller than 

 Chrysis hidenfata, whose food is the larva of the wasp. 



Mr, Stone found a "minute larva" grow to full size in 

 forty-eight hours — on which ^Ir. ^lurray remarks that it is so 

 opj)Osed to every thing we know of the laws of development 

 and assimilation that he cannot accept it. Now I am unable 

 to give Mr, Murray any facts that will expand his faith in the 

 laws of development and assimilation quite to the extent re- 

 quired; but I am able to give him some that will so nearly do 

 so, that he Avill, I doubt not, like myself, be })rcj)ared to be- 

 lieve that Mr, Stone's account is literally true. I may first 

 say that jjrobably Mr. Smith felt little difficulty in accepting 

 Mr. Stone's ob.servations, as he must be accustomed to the 



