OCEAN LIFE. 13 



has at first precisely the appearance and structure of the rest of 

 the stalk of the Zoophyte, being filled with granular matter, and 

 exhibiting in its interior the circulation of globules already de- 

 scribed, moving towards the extremity along the sides of the tube, 

 and in an opposite course in the middle ; the end of the branch, 

 however, before soft and rounded, soon becomes perceptibly di- 

 lated. After a few hours, the branch is visibly longer, its extre- 

 mity more swollen, and the living pith is seen partially to have 

 separated itself from the sides of the tube, the boundaries of which 

 become more defined and undulating. The growth still proceed- 

 ing, the extremity is distinctly dilated into a cell, in which the 

 soft substance seems to be swollen out, so as to give a rude out- 

 line to the bell-shaped Polyp, but no tentaculae are yet distin- 

 guishable. A rudimentary septum is now visible, stretching across 

 the bottom of the cell, through the centre of which the granular 

 matter, now collected into a mass occupying but a portion of the 

 stem, is seen to pass. The Polyp and cell gradually grow more 

 distinct, and the tentaculse become distinguishable. As the de- 

 velopment proceeds, the tentaculae become more perfect, and the 

 Polyp at length rises from its cell to exercise the functions for 

 which it is destined. The third mode of multiplication, or that 

 by reproductive gemmules, seems to be especially adapted to the 

 diffusion of the species, and is peculiar to Zoophytes of this de- 

 scription. At certain periods of the year, besides the ordinary 

 cells which contain nutritive Polyps, others are developed from 

 different parts of the stems, which may be called female or fertile 

 Polyps, although usually simply termed the vesicles. The cells 

 of this kind are much larger than the nutritive cells, and of very 

 different forms; they are, moreover, deciduous, falling off after 

 the fulfilment of the office for which they are provided. They 

 are produced in the same manner as the rest of the stem, by an 

 extension of the tegumentary membrane, which, as it expands 

 into the form of the cell, becomes of a horny texture. It may be 

 traced, however, over the opening of the cavity, where it some- 

 times forms a movable operculum." 



Now, within this tall, transparent, vase-like capsule, by a series 

 of gradual changes, the common nutrient flesh develops a very 

 peculiar embryo. " When somewhat mature, the permeating tube 



