214 Prof. H. James-Clark on the Spongie ciliate. 
tions was 2.30 P.M. By 2.35 P.M. (fig. 54) the larger fla- 
gella (ff) had separated still further, and the smaller cilium 
had split into two (jl!) very conspicuous filaments, as yet, 
however, attached to a common point of the body. From this 
time forth to the completion of the process of fissigemmation 
all of the cilia kept up a slow vibration, in which they undu- 
lated from base to tip with a sort of snake-like motion. By 
2.45 P.M. (fig. 55) the body had become quite appreciably 
broader than long, the contractile vesicles (cv) were widely. 
separated, and the smaller cilia had left between them a con- 
siderable space, and each one had approximated quite near to 
the base of a larger flagellum. At 2.50 P.M. (fig. 56) the 
body had become nearly twice as broad as long, and the space 
(ce!) between the two pairs of cilia was nearly twice as great 
as in the last phase, and considerably depressed in the middle, 
so that the body had a broadly cordate outline. By 2.52 p.m. 
(fig. 57) the posterior end of the body (at a point a little to 
one side of the spot where it was attached to the pedicel) was 
also slightly indented, so that in outline it presented a guitar- 
shaped figure, each rounded half of which bore a pair of un- 
equal cilia, and contained a contractile vesicle. In one minute 
more the contraction had increased to such an extent that the 
body was divided about halfway through (fig. 58). By 2.54 
P.M. (fig. 59) the animal had a dumb-bell shape, and the 
pedicel (pd) was attached to one of the segments near the 
point of constriction. Still the process went on very rapidly, 
and by 2.55 p.m. (fig. 60) the new bodies were widely sepa- 
rated, but still attached to each other by a mere thread. At 
3 P.M. (fig. 61) the body which was attached to the pedicel 
was left alone, and its companion swam away to seek a new 
attachment and build up its stem. 
“To the last moment the hyaline envelope remained about the 
segments, and in fact so long afterwards that time and circum- 
stances did not allow me to ascertain its final disposition. [ 
would remark, however, that when the ovate bodies of the 
half-grown monads (fig. 49) are contracted temporarily into a 
globular shape, they appear identical (excepting that they 
lack the hyaline envelope) with these recently fissed forms. 
In all probability, therefore, the latter lose their envelope and 
assume the shape of the former. 
** As to the development of the stem, I think it quite cer- 
tain that it grows out from the posterior end of the body. The 
best proof of this is, that I have frequently found a monad 
(especially in the condition of the one which I described above 
as breaking loose from its companion) nearly sessile upon a 
clean spot, and attached by a very short, faint, film-like 
Ee ee a Py) ee i ae ee 
