194 DISCHARGE OF THE EGGS. 



ovigerous vesicles of so large a size that I at once 

 isolated the head in hopes of witnessing the develop- 

 ment of the embryo. 



The capsules showed the same structure, but as 

 one was larger and evidently more developed than the 

 other, I selected that one for particular examination. 

 (Fig. 5). It was perfectly spherical, with a short 

 footstalk, through which a neck of dark brown sub- 

 stance connected with the central nucleus, which 

 was also dark brown, round or slightly oval, and well- 

 defined. This nucleus is not an aggregation of ova, 

 as Dr. Johnston seems to suppose (Br. Zooph. 39), 

 but a sort of placenta around which many ova are 

 arranged, in the manner shown at Fig. 5 (representing 

 for clearness' sake a section). These ova fill the 

 whole space between the nucleus and the walls of the 

 capsule ; they are of a clear, yellowish-brown hue, 

 slightly granular in texture, rondo -triangular in form, 

 with one angle resting on the placental nucleus. 



I had not been watching the capsule many minutes 

 before its gelatinous walls burst at the side the 

 farthest from the footstalk; and the ova began to 

 issue forth in quick succession, as shewn at Fig. 6. 

 It appeared that the elasticity of the walls was the 

 inmaediate cause of their exit, for they w^ere evidently 

 pressed out ; and towards the end of the process when 

 few remained, the collapse of the walls became quite 

 evident, and when the last ovum was excluded, the 

 capsule had shrunk up so as to leave scarcely any 

 appreciable space between the skin and the nucleus, 

 which latter remained unchanged 



Twenty five ova were thus excluded from one cap- 



