with a description of a new species o/Laomedea. 83 



ture were readily determined. They will be understood by a 

 reference to PI. III. %. 3. 



The column {a) which traverses the centre of the vesicle is a 

 membranous tube containing granular matter, — a prolongation 

 of the animal substance which permeates the creeping stem. 

 Through this flows the stream of nutrient particles. Imme- 

 diately below the orifice it expands into a kind of pouch {b), 

 which in the living state is filled with granular matter. When 

 emptied of its contents, it appears as a delicate membranous sac 

 within the vesicle. A kind of neck (c) connects this with the 

 mouth of the vesicle and the external ovigerous body {d). In 

 the centre of the latter is a distinct cavity (e) within which the 

 ovum is contained. The external envelope (/) is of varying, 

 often of considerable, thickness. From the lower part of the cen- 

 tral cavity a canal {g) passes downward and opens into the gra- 

 nular mass {b). The lower extremity of the ovum, which is 

 somewhat produced, just penetrates this canal at h, and through 

 this channel and at this point the nutrient stream finds entrance 

 to the ovum. Such is the structure of the vesicle. 



The following is a summary of the results obtained with re- 

 spect to the propagation of Campanularia Syringa : — 



1. At certain seasons oval vesicles are produced in great 

 abundance on the creeping fibre, into which an offshoot ft'om 

 the common animal substance penetrates, — a membranous tube 

 containing granular matter. 



2. After a time this offshoot expands at the top into an oval 

 body, in which granular substance accumulates, and through 

 which the nutrient stream circulates. 



3. This body gradually enlarges, and at length passes beyond 

 the mouth of the vesicle, where it remains attached, receiving- 

 supplies of the nutrient fluid through a canal which descends 

 from its lower extremity. 



4. In the course of its development a portion of the granular 

 substance is aggregated into a central nucleus separated from the 

 rest of the structure and lying in a distinct cavity. Nourished 

 by the general circulation this is matured into a perfect ovum, 

 which at length escapes through the ruptured walls of the con- 

 taining sac. 



The ovigerous body must increase considerably, — probably un- 

 dergoes most of its development after passing beyond the mouth 

 of the vesicle, for it is often met with of such a size that it could 

 not be contained within. 



With respect to the membranous pouch inclosing granular 

 matter, which always occurs immediately below the orifice, it is 

 no doubt the early stage of an ovigerous body destined to suc- 



6* 



