MOSS ANIMALS 



3395 



Round- 

 Mouthed 

 Group 



perhaps they may be specialized tactile organs, or may help to drive the minute prey 

 within reach of the nutritive individuals. Lastly, we have the ovicells or egg 

 receptacles, which are found at the lower ends of the zocecia in the form of bells, 

 helmets, or vesicles. It is uncertain whether these are independent modified indi- 

 viduals or merely appendages of the zocecia, the latter view being the more 

 probable. 



Another suborder of the Gymnolaemata consists of the Cyclostomata 

 or round-mouthed Bryozoans. In the tube-like forms ( Tubulipora}, 

 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 incrustations, the individ- 

 uals radiating outward as seen in the mag- 

 nified 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 

 before 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 dis- 

 tance. The other germinal bodies, termed statoblasts, form as cell masses on the 

 strand known as the funiculus, which hold 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 color, 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. 3396. The edge running 



Tubulipora verrucosa. 



Part of a stock (magnified); b. A few cells (highly 

 magnified); c. A stock (natural size). 



