42 ZOOLOGY 
cells may be noticed withdrawing their pseudopodia, and passing 
into a spherical resting condition. These form the ova. Others 
Fig. 33.—Various forms of Sponge spicules. 
divide up into an immense number of spermatozoa (Fig. 35), each 
with a head and long vibratile tail. In Grantia labyrinthica 
AG 
\\ 
Fic. 34.—Sections through horny fibre of Dendvilla. A, Longitudinal section ; 
layers of spongin, surrounded by a layer and surmounted by a cap of spongo- 
blasts; «@, fibrous sheath. B, The same in transverse section. After Von 
Lendenfeld. ; 
Dendy has described the ripe ova making their way through the 
mesoderm to the epithelium of the inhalent canals, and passing 
