424 
MOLL USC O IDE A. 
Tubulipora verrucosa. 
a, Part of a stock (magnified); b, A few cells (highly 
magnified); c, A stock (nat. size). 
which may be taken as typical of this suborder, the relation between the infolding 
portion of each individual and the rigid cell differs from that in the Chilostomata; 
and the aperture of the cell is terminal and wide, passing into the soft anterior end 
without narrowing. Tubulipora is one of 
the numerous round-mouthed forms, the 
stocks of which form cup-shaped incrusta¬ 
tions, the individuals radiating outwards as 
seen in the magnified figure (a). In Fig. b, 
several cells are still more highly magnified. 
Fig. c shows the natural size of the colony. 
The moss-animals seem to be excep¬ 
tionally rich in methods of reproduction. 
There is, firstly, the sexual reproduction 
above mentioned; secondly, the multiplica¬ 
tion of individuals by budding and stock 
formation; and, thirdly, a peculiar repro¬ 
duction, found in fresh-water forms, in 
adaptation to external conditions, enabling 
the animals to tide over the cold of winter, 
or the drying up of ponds, etc. This last 
method deserves description. It is effected 
by means of germinal bodies, which may 
be of two kinds. In the genus Paludicella, 
the germs are produced in the course of a few days at the end of September by 
simple constriction or breaking off of portions of the stock, which then perishes. 
These detached portions vary greatly in size, and resemble buds of the same size, 
which latter however remain connected with the stock. They are, in fact, detached 
buds, called winter-buds, which adhere to the dead remains of the horizontal creeping 
stem of the Paludicella stock, and the next spring either grow out at the same place 
into new colonies, or are swept away by the water to form fresh colonies at a 
distance. The other germinal bodies, termed statoblasts, form as cell-masses on the 
strand known as the funiculus, which holds the stomach in place, also at the end 
of September. They are round or oval in shape, and become surrounded by a 
peculiar horny transparent shell, which is brown or yellow in colour, and consists of 
two valves fitted one upon the other like watch - glasses. A number of these 
statoblasts may be seen inside the colony in the illustration on p. 425. The 
edge running round the two valves is often widened and contains small air-chambers, 
or else horny filaments which stand out radially and have barbed tips. This ring is 
termed the swimming-belt, and is a hydrostatic apparatus, which supports these 
winter-buds or statoblasts on the surface of the water. The complicated barbed 
hooks apparently act as anchors, by means of which the passively swimming 
statoblasts catch on at points suitable for their development during the course of the 
next spring. As soon as the time for development comes, the two valves split apart, 
and the germinal mass emerges from between them. Here, then, we have an alter¬ 
nation of generations. Out of the winter-buds and statoblasts asexually produced 
individuals arise, which then reproduce themselves sexually, their descendants again 
