26 W. G. RIDEWOOD. 
on the plume-axes and on the pinnules, but they occur in greatest abundance in the 
dorsal layer of the buccal shield. 
The red colour of the curved line of the buccal shield and that occurring in 
the oviducts is due to closely crowded granular cells of small size, of uniform 
character, and of a bright red colour which remains, or, at most, has turned to a 
reddish brown, in sections cut by the paraffin method. In the material fixed by 
picric acid solution the cells are not swollen, but present the same appearance as 
in that fixed by formalin or by Perenyi’s fluid. 
Except in the case of a small number of polypides found loose at the bottom 
of the bottles—specimens which had clearly escaped from their tubes at the 
moment of immersion of the colony in the preservative fluid (fig. 14, plate 4)—and in 
polypides taken from the terminal tubes of the colony (fig. 15), the stolon does 
not stand out obliquely or hang ventrally as it does in Cephalodiscus dodecalophus, 
but it runs back parallel with the long axis of the body (figs. 7 and 8, plate 3). On an 
average of cases it leaves the body midway between the hind edge of the buccal 
shield and the end of the visceral mass. It is short, stout, and transversely 
wrinkled: in much contracted specimens the visceral mass partially envelopes the 
stolon, a concavo-convex flap of it lying against one or both sides of the stolon. 
On the other hand, in the above-mentioned individuals which appear to have died 
free, and uninfluenced by the limitations imposed by the tubes (fig. 14), the 
visceral mass is not distorted by the stolon, and, further, it has a general curva- 
ture towards the ventral side of the body. 
There is a striking uniformity in the general appearance of the fully-grown 
individuals. Full-grown polypides that have not two or more buds and a_ pair of 
gonads in mature condition are not met with, and the regular presence of ripe 
gonads in individuals which are actively budding is not the least remarkable feature 
of Cephalodiscus. Further, although large ova are frequently encountered lying 
loose and singly in the blind ends of the tubes of the colony, they appear to be 
all of the same age, and exhibit no signs of segmentation. 
A polypide remains as a bud until its plumes are almost of full size, and 
until itself is nearly as large as the individual to the end of whose stolon it is 
attached. Such a “ripe” bud usually carries at its point of contact with the main 
stolon a very small bud of its own, and it has gonads about one-fourth or 
one-third of the normal size. 
Although throughout the colony, and not merely at the apices, the polypides 
are producing buds, it is only at the tips of the branches that one meets with what 
may be regarded as newly established polypides. A polypide from one of the 
terminal tubes of a branch of the colony differs from ordinary polypides, in that 
there are no gonads recognisable by dissection,* the visceral mass is more swollen 
* This is odd, in view of the fact that small gonads can be recognised in ripe buds not yet separated from the 
parent stolon. 
