between Wasps and llhipiphori. 85 



scription. Neither does Westwood give or refer to any descrip- 

 tion in his great work ; and I can find none anywhere else. 

 Mr. Stone is the first who gives some details about it: his 

 description is as follows : — 



" The larva is a singular-looking one. The head is bent 

 forward under the body ; between the segments it is more 

 dee[)ly furrowed than any larva with which I am acquainted. 

 A longitudinal furrow extends down the back from the head 

 to the anal extremity, cutting each segment across. The skin, 

 during lite, throughout the whole of the course of this furrow, 

 is pei-fectly transparent, so that the workings of the internal 

 organs may be plainly seen. The body of the larva, while alive, 

 has tlie apjjearanec of a thin transparent skin filled with mi- 

 nute particles of curd. These appearances vanish after death, 

 wlu'n the body becomes dense and has an a})pearance of soli- 

 dity about it which it had not before." (Stone in ' Zoologist,' 

 18(J5, xxiii. p. 9462.) 



But this descri})tion is obviously imperfect. He does not 

 tell us whether it has feet or not — a not unimportant point 

 when the question is whether the larva passes a nearly mo- 

 tionless life in one cell, or a roving one, preying upon grubs 

 in other cells. But the context implies that it is like the 

 grub of the wasp, and consequently apodal ; and Mr. Smith 

 informs me that it is so. I remember perfectly, in my exa- 

 mination of the wasps' nest out of which this question has 

 arisen, seeing plenty of grabs Avith the back so transparent as 

 to show the inside like curds shining through. If these A\ere 

 the larvae of the Rhipijihorus^ then they are as like to the wasp- 

 grub as one pea to another — so like, in fact, that they did not 

 attract my attention as being distinct. Their powers of mo- 

 tion, then, are similar to those of the wasp ; and I state it as a 

 fact beyond contradiction that the wasp-grub cannot walk. 

 When taken from its cell, it lies like a sack of meal : it may 

 wriggle a little ; but as to rising up and walking, it can no 

 more do it than the sack can. Once fixed and hanging by 

 the tail, all they can do seems to be to shift their position a 

 little. But, passing that, the question I ask is, how the Rhi- 

 ptjjhorusAavY&i are sustained at first until they reach their 

 supposed prey, if not by the wasp-nurses. The journey 

 of the young larva, according to Mr. Smith's view, is in 

 an opposite direction to that of the wasp's, viz. to the 

 mouth of the cell, to go roving about in search of a wasp- 

 larva on which to pounce and prey ; its journey is thus 

 longer. It must be a longer time without food, and undergo 

 greater exertion requiring food, travelling about like a Blondin 

 on the edges of the cells — only like a Blondin upside down ; 



