ON FAEAWIUGHTIA JJOBUSTA. 



203 



111 the case of the male gonophores, I liave never fouiul 

 sucli large capsules as occur in the female gonophores. 'I'heir 

 final growth appears to be much reduced, and they do not as 

 a rule exceed 10 to 12^ in diameter. In some of these 

 smaller forms the concentric lamination, especially towards 

 the centre, is replaced by a radial striation (PI. XXXIV, 

 fig. 8 (6^ 9, 10), and text-fig. 5 (6') ). In figs. 9 and 10 of the 

 plate the central body has split up {d. h.) preparatory to the 

 formation of §poi'e-like bodies. In correlation with the small 

 size of the capsules in the male gonophore it may be noticed 

 that there is but little space for development, as the umbrella- 



Text-fig. 6. 



u.c. Umbrella-cavity, c.h. Central body, supposed Schizophyte. end.l. 

 Endodermal lamella, n. Nematocysts. sh.sp. Shrinkage space be- 

 tween capsule and hydroid. x 750. 



cavity is very restricted. It is interesting to note this 

 adaptation to the environment. 



In one female gonophore a capsule was found embedded in 

 the ectoderm at the future opening of the umbrella-cavity. 

 It differed from the capsules growing free in the umbrella- 

 cavity in the almost complete absence of the outer compact 

 layer, and in the layers of the capsule being apparently more 

 separable from one another. 



The real nature of the central bodies and capsules is 

 problematical. The central bodies are, as we have seen, 

 highly refringent, and stain in section only w^ith difficulty. 

 The structures in a young condition can be embedded and cut 

 with a microtome fairly well, but in an older condition, when 



