OR lilPE-HISTORT OF CERTAIlSr ACARINA. 387 



examined this cell on the 28th April, and found that the eggs 

 had mostly hatched, and that the cell contained a number of 

 hexapod larvae which were unknown to me : all the three legs 

 had didactyle claws. This creature is described below and is 

 iigured at PI. XV. fig. 1. These larvae grew rapidly, and ou the 

 1st May I found that some had become inert and had swollen up 

 into mere shapeless lumps, as is common with the Acarina before 

 the ecdysis. I expected to see an octopod nymph emerge from 

 this inert creature, but on the following day (May 2nd) two so- 

 called Hypopi, exactly like those caught on the bee, emerged 

 from the inert larvae, and more subsequently emerged. I found, 

 however, that some, when they emerged, were very different from 

 the supposed Hypopi, and were not creatures enclosed in a hard 

 carapace any more than the larvae had been. This puzzled me, as 

 it appeared as if it must be the nymph, and as if I had missed 

 that stage in the other specimens *. From what I subsequently 

 observed, however, the supposed nymphs appear to be the males, 

 although so very different from the females as not to be sus- 

 pected at first. This male is described below, and figured, PL XY. 

 fig. 2. 



This creature has the posterior part of the abdomen covered by 

 a brown shield-shaped plate, which makes it very conspicuous 

 amongst the larvae ; it also has tlie hind legs very thick and 

 peculiar in form, but they are terminated by setae, not claws nor 

 suckers. It is smaller than tbie adult female, and even than the 

 larva in its final inert, swollen condition. "While I imagined this 

 to be the nymph I put several specimens, in many instances, into 

 separate cells, hoping to see them change into adults. Nothing of 

 the kind, however, took place ; they lived for some time, aud then 

 died, but without change. In the meantime, however, I began 

 to observe that, among those which had not been separated, one 

 of these supposed nymphs, with the brown abdominal plate, was 

 frequently attached to a white inert larva, the singular hind legs 

 of the nymph grasping the larva, which the nymph dragged about 

 with it wherever it went. At last this became so general that 

 there was hardly an inert larva in the cells that was not in the 

 possession of one of the brown-tailed forms. These facts, 

 taken together, naturally led me to the conclusion that I had 

 probably really got the male, not the nymph ; and an examination 



* This appeared more probable, as the nymphal stage occurs in almost all 

 other Acarina with which I am acquainted. 



