OF GLYCIPHAGUS DOMESTICUS AND a. SPINIPES. 



291 



escaped out of the cuticle of one of these inert nymphs, the 

 others soon followed. The cast skin from which the adult 

 emerged was thin and fine, very different in appearance from that 

 of the cases. One point at least had now been established, viz. 

 that the cases were a penultimate nymphal stage — i. e. that the 

 nyinpb. which emerged from the case became adult at its first 

 ecdysis. 



While these observations were in progress I also endeavoured 

 to obtain a knowledge of the matter by dissecting the cases and 

 their contents; bat as, in order to avoid any chance o£ error, I 

 have lately repeated these dissections on a large number of speci- 

 mens, I will describe the results of both together in order to avoid 

 repetition. 



At this time I w^as forced by other engagements to abandon 

 the investigation temporarily ; and I did not make any further 

 observations on the same species until the present year (1888). 

 On January 25, 1888, I placed ia a cell four cases taken from 

 fresh material which I had obtained, but which contained very 

 few cases, some of which I reserved for dissection ; but in spite 

 of my providing them with gentle warmth and slight moisture, 

 such as would apparently form the most favourable conditions, 

 these cases still (May 3) remain in the same condition as when 

 placed in the cell*. On April 9, having found that a great many 

 cases had now formed in the same material from which the last 

 had been taken, I placed a number of these in three sepaiate 

 cells. On 21st April I found an inert nymph of G. doinesticus in 

 one of these cells which had escaped from a case, and must have 

 emerged and become inert ^ince the cell had been last examined, 

 which happened to be two days ; longer than usual. On the 26th 

 April the adult emerged, and a second nymph had emerged and 

 become inert prior to the final ecdysis. On the 1st May an adult 

 female of G. domesticus emerged from this last-named nymph. 

 I carefully examined it and made certain of the species. 



Between the commencement of January and the end of April 

 1888, 1 dissected a large number of these cases of G. domesticus ; 

 the results were entirely confirmatory of those which I had 

 obtained in 1885 — viz., that inside each full case, and almost 

 filling up the anterior portion of it, but not the legs, which were 

 empty, was a protoplasmic mass which had a transparent, colour- 

 less, and almost structureless cuticle. This mass had a rounded 



* They subsequently emerged on 15th July. 

 LINN. JOUKN. — ZOOLOGY, VOL. XX. 23 



