192 



EENEST WAEKEN. 



from the parent coenosarc in a closely similar manner. A 

 bud is formed by an outgrowth of the coenosarc, which pushes 

 its way through the perisarc, partly by mechanical pressure, 

 and partly, I think, by absorption (text-fig. 8, a). The bud 

 is at first covered merely by a very thin membrane {c). In 



Text-fig. 2. 



A. Adult hytli-autli of Eudendriiim sp. b. Developing hydrauth of 

 Parawrightia robiista. 



c.en. Central endoderm. /.en. Fan-shaped endoderm. r.e. Reflexed 

 ectoderm, t. Tentacle, j:*. Perisarc, consisting of the vertically 

 striated layer chiefly, jj.g. Perisarc groove, d.g. Digestive cavity. 

 X 140. 



the case of a lateral branch of the stolon the bud can readily 

 mould itself so as to fit into any irregularities of surface of 

 the foreign body which supports the hydroid. In this way 

 the colony becomes very firmly attached (PI. XXXIII, 

 fig. 2,r/.r.). 



