560 
PROFESSOR ALLMAN ON THE STRUCTURE 
Following now the female gonophore in its development, we find that in the next 
stage (fig. 3) both it and its included gonogenetic cavity have increased in volume, while 
the floor of the cavity projects further into its interior in the form of a hollow conical 
core. This is easily recognized as the spadix; on the free surface of the cavity of 
the spadix (c) villi-like processes similar to those which occur in the general cavity are 
abundantly developed. The gonogenetic cavity has now become uniformly filled with 
a plasmatic mass (#), which is seen to consist of a multitude of nuclei (fig. 5) about 
3 5 \ 0 of an inch in size, each enclosing a minute nucleolus, and immersed in a minutely 
granular protoplasm. An extremely delicate structureless hyaline membrane (fig. 3, d) 
can now be traced over the whole surface of the generative mass, which it thus sepa- 
rates from the proper endodermal walls of the gonogenetic chamber. 
As yet no distinct cell-boundaries can be detected in the contents of the gonogenetic 
chamber, and the nucleolated nuclei afford the only evidence of cell-differentiation. 
With the enlarging gonophore, however, the protoplasm which surrounds the nuclei 
increases in volume, and we soon begin to discover in it manifest cell-boundaries (fig. 4). 
Every nucleus is now surrounded by a differentiated mass of protoplasm, and the cavity 
of the gonophore has thus become filled with bodies which possess all the characteristic 
features of true ova, each with its well-defined germinal vesicle and germinal spot and 
its surrounding vitelline protoplasm. 
These ova-like bodies continue to increase in size with the growth of the gonophore. 
They remain for some time closely pressed against one another, having thus acquired a 
polyhedral form (fig. 6) ; but they gradually become looser, assume an oval shape 
(figs. 7 & VI, f), and may be easily isolated by the needle or by the mere action of the 
compressor. Their germinal vesicle is now very large and distinct, and within the large 
germinal spot a well-defined spherule or nucleolina may be easily detected. Though 
their subsequent history differs in some points from the characteristic development of 
the ovum such as is met with in other animals, we should yet be scarcely justified in 
denying to them the significance of true ova. 
They have no soonet attained their complete independence and acquired their full 
size in the sporosac, than they begin to present a very remarkable phenomenon. They 
lose their independent existence, and begin to undergo a fusion into one another ; and 
when the contents of the sporosac are now liberated by rupture under the microscope, 
many of these nucleolated protoplasm masses may be seen united to one another by irre- 
gular pseudopodia-like extensions of their substance (fig. 8). By the gradual shortening 
and thickening of these processes the little masses which they connect are drawn closer 
to one another, and end by becoming completely fused together into a common proto- 
plasmic mass (fig. 9). In this mass the cell-boundaries are completely lost, but numerous 
nucleolated nuclei are scattered through its substance. These are almost certainly the 
nuclei with their included nucleoli of the original independent protoplasm masses or ova. 
The fusion commences among the ova which lie in the immediate vicinity of the 
spadix, to which the masses formed by their union continue for some time to adhere by 
