NES el ee Ee ee Lie UN phe gt Pe Meme oor s pate et em it oes Ne eM neh 
as Infusoria flagellata. 195 
(fig. 10, cv) of these vesicles are found together; but it has 
always been evident at such a time that the body was prepa- 
ring for fissigemmation (figs. 9,10), and that the increase in 
number of these organs arose from the fact that one of them 
had already undergone self-division. In another genus (Sal- 
pingeca, S. marina, nov. sp., figs. 28,29,30) no less than four 
contractile vesicles (cv) have been observed to arise from two, 
under the same circumstances. 
The systole of each vesicle of Codosiga occurs regularly 
once in half a minute, and usually that of one alternating 
with that of the other. Both the systole and the diastole pro- 
ceed very deliberately, each, however, not occupying more than 
a few seconds. During the interval between the end of the 
diastole and the beginning of the systole the vesicles have a 
rather irregular, indefinite, spheroidal outline ; but just at the 
moment of systole they assume a sharply defined and perfectly 
globular shape, and raise the surface of the body into a quite 
perceptible bulge. During this momentary expansion a vesicle 
equals at least half the greatest diameter of the body. 
The reproductive organ, if we are not mistaken in our inter- 
pretation, is seated at the posterior end of the body, behind the 
contractile vesicles. It is a globular, highly transparent body 
(figs. 23, 24, n), and sometimes almost fills the space on each 
side of it. That it is solid, and not a mere vacuole, appears 
conclusive from its resilient action after being indented by the 
expansion of the contractile vesicles. It should be mentioned 
_ that this body was not observed in the fresh specimens which 
were collected in December, but appeared to be constant in 
some stale examples which had been kept on hand for two or 
three months. 
The peduncle (fig. 8, pd), or main support of the colony, and 
the pedicels (pd*) or immediate bearers of the individuals, 
_ share in the general gamboge-yellow colour of the latter, and 
also in their vitality. The latter statement has been verified 
fully in regard to the pedicels, by seeing them split down to 
their bases after the a proper has undergone self-division ; 
and in regard to the peduncle, although only one observation 
was made, and the splitting was followed in its slow course 
downward for only a short distance, it was evident, from its 
much more than usual thickness and the presence of a distinct 
median furrow which extended to its very base, that it even- 
tually would divide into two stems. The length of the 
— varies from a mere disk, when it begins to develope 
om the base of some newly settled Monad, to five or six 
times the length of an individual. It always carries a single 
body until it is at least three or four times its length (figs. 9, 
