DR. ALLMAN ON THE ANATOMY AND PHYSIOLOGY OF CORDYLOPHORA. 373 
ORGANS FOR THE PRESERVATION OF THE SPECIES — EMBRYOLOGY. 
The researches of modern naturalists, especially of Ehrenberg, Loyen, Van 
Beneden, Sars, and Dujardin, have thrown much light on the embryology of the 
inferior zoophytes, and their observations have brought to our knowledge m.any 
remarkable and unexpected facts, though physiologists are by no means of one mind 
as to the true signification of several of the facts with which we have thus become 
acquainted. 
During the later summer and autumn months Cordylophora lacustris may be seen 
with numerous oval capsules borne upon the ultimate or polypiferous ramuli, fig. 2. 
Each ramulus generally carries one, two, or three of these capsules, which are 
situated alternately on either side of the ramulus at some distance behind the body 
of the polype, and where the branch is still covered by tbe polypary, the more 
advanced capsules being always nearer to the main stems. They are nearly sessile 
on the supporting branches, and when fully developed are somewhat larger than ihe 
club-shaped bodies of the polypes. They are surrounded externally by a delicate 
continuation of tbe polypary, and as they approach towards maturity are found to 
contain within them either ova or spermatozoa. 
The structiii'e and development of these capsules and their contents are exceedinsrly 
mteresdng. The capsule on its first appearance presents itself as a small tubercle, 
consisting of a simple hernia-like protrusion, or diverticulum of the coenosarc (fig. 1 1 u) ’ 
enve oped by a delicate production of the polypary (fig. u b), and as the cavity of 
the diverticulum continues to communicate with the common canal of the branch 
the contents of the latter pass freely into its interior. As the tubercle increases in 
size, we perceive that the external investment from the polypary immediately sur- 
rounds a sac of distinctly cellular structure, having the diverticulum from the coenosarc 
projecting into it below, and having a remarkable system of branched tubes developed 
on Its internal surface (figs. 12, 13, 14). These tubes spring from the sides of the 
diyeiticulum with whose cavity their own communicates ; they occasionally inosculate 
wi one another, and passing upwards in close connection with the walls of the 
cellular sac, extend to the summit of the sac where their branches terminate in creca; 
eyare lined with a layer of cells, which contain secondary cells and brown granules 
and which thus resemble the general endoderm of the zoophyte. Thread-cells occur 
in he walls of the cellular sac, which is plainly referable to the ectodermal system. 
e ween t e cellular sac and the diverticulum is a considerable interval, which is 
filled with a granular fluid. 
^ We next find that in those capsules which are to contain ova a number of sphe- 
rical dark grey or bluish bodies (fig. 14/) have become apparent in the midst of the 
m c ^ perceive the germinal vesicle 
e orm o a minute clear point, but the germinal spot is not apparent. The 
germina vesic e soon disappears, and when the ova are now examined, the pheno- 
