o/" Rhipipliorus paradoxus. 195 



rapid feeding-up which occurs in so many Hymenoptera. I, 

 on the other hand, was as much astonished at my own obser- 

 vations on the Chrysides as Mr. Murray can be incredulous of 

 the facts recorded by Mr. Stone. The larva of Chrysis hi- 

 dentata began to spin its cocoon in eleven days from the date 

 of the egg-hatching. Chrysis neglecta took rather a shorter 

 time. But in one instance in which I reared a larva of Chrysis 

 ignita, and happened to know the date on which the Qg^g was 

 laid, I found, two days after that date, a " minute larva " 

 {^ inch long, about one-thirtieth of the full-grown larva in 

 bulk), and \\\f(mr more days the larva was full-fed. 



On Mr. Murray's next point, as I have no fresh light to 

 throw on it, I will merely remark that, as I read the recorded 

 facts, the larvte that Mr. Stone found unemployed in eating 

 wasp-larvae were not larvas that had still some eating to do, 

 but were those that had, as Mr. Murray expresses it, eaten up 

 their man and retired from active life ; though not yet pupte, 

 they were about to enter that state. All larvse take a pro- 

 longed rest at this stage of their existence. Mr. Murray, who 

 will not allow that a larva can feed up in two days (not from 

 the Qgg, but from a small size), surely does not ask us to sup- 

 pose that the larva becomes a pupa the instant it has done 

 feeding. Chrysis, which fed up in four days, remains before 

 its change to pupa nearly ten months. Will he not allow 

 Bhipijihorus a day or two '? 



I do not see that the question of size has much bearing upon 

 the question at issue. In the one view the large specimens 

 are large because they have eaten a queen instead of a worker 

 larva, in the other the wasps have fed them more plentifully 

 because they were in queen-cells. Still, if the capacity of 

 parasites for varying in size which Mr. Smith mentions be not 

 called in by Mr. Murray to account for those in the queen- 

 cells being able to assimilate a larger supply of nutriment 

 than the others, he must give us some other hypothesis. The 

 case is obviously not parallel to that of the wasps, where the 

 larger insects are queens, the larger Rhipijjhori differing only 

 in size. So much has this difficulty been felt, that I have 

 seen it somewhere advanced that the larger specimens are 

 always females — making the case parallel with that of the 

 wasps themselves, which Mr. Murray has proved not to be 

 the case. Why, if difference of feeding can produce the result, 

 Mr. Smith should be asserted to be carrying his argument to 

 the extreme in supposing that the mere difference between 

 eating a worker-grub and a queen-grub is sufficient to account 

 for the greater dimensions of the one in the queen's cell over 

 the one in the worker's cell, I cannot at all understand, A 



