OF GLYCIPHAGUS DOMESTICUS AND G. SPINIPES. 
291 
escaped out o£ 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 
nympb 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; but as, in order to avoid any chance of 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 was 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 in 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 separate 
cells. On 21st April I found an inert nymph of G. domesticus in 
one of these cells which bad escaped from a case, and must have 
emerged and become inert since 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. JOtJKN. — ZOOLOGY, VOL. XX. 
23 
