404 WILSON. 
EXPLANATION OF PLATE XXIV. 
(Aircinia acuta.) 
Fic. 116. Section of immature ovum, surrounded by numerous mesoderm 
cells. D.4. 
Fic. 117. Section showing mature (as to size) ovum in situ. A.4. 
Fics. 118, 118’. Two sections of mature ova showing stages in the extrusion 
of the second nucleolus. D.4. 
Fic. 119. Section through part of ripe egg with surrounding follicle. D.4. 
Fic. 120. Section through segmenting egg. C.4. 
FIGS, 121, 122. Sections of morulas. C.4. 
