170 SEA-SIDE STUDIES. 



were, however, obtained, which, being attached to sponges, 

 were easily stripped from the rock, and witli them were asso- 

 ciated a great number of very small specimens. Not long- 

 afterwards the author noticed a number of young surround- 

 in o- a laro;e white dianthus in the Vivarium of a friend at 

 Leith, and was told that the Actinia, while moving round 

 the tank, had left behind it small white bodies, which separ- 

 ated themselves from the foot or sucker and became young 

 Actinias. Sir John Dalyell had described a similar mode of 

 multiplication in Actinia lacerata, and HoUard in Actinia 

 rosea (?) The former writer had observed that Actinia la- 

 eerata protruded from all parts of its foot, stolons or suckers, 

 which became detached, and presently put forth tentacles, 

 and were developed into minute Actinias. After reading 

 Sir Jolm Dalyell's account of Actinia lacerata, Dr Wright 

 was anxious to acertain whether there might not be included 

 in the prolongations separated from the foot, either true ova 

 or germs, or some tissue specialised for the production of 

 young. In the hydroid zoophytes, such as Hi/dra, Coryne, 

 &c., the walls of the body consisted of three elements or 

 layers, — a dermal or integumental, an areolar or muscular, 

 and a mucous or intestinal layer ; and when gemmation took 

 place in these animals, it occurred by the protrusion of a 

 simple diverticulum or sac from the canal of the body, formed 

 of all the three elements. Tliis diverticulum was developed 

 into a polype body, with mouth and tentacles like those of 

 the polype, from which it pullulated ; the two bodies having 

 the digestive canal and all the tissues continuous with 

 each other. In Hydra tuba multiplication took place by 



