794 PROFESSOR W. C. M‘INTOSH AND MR E. E. PRINCE ON 
form, in fact, the germinal epithelium, but a definite germinal ridge cannot be made out. 
Indeed, in the haddock, it is not until the second or third week after extrusion that this 
germinal portion becomes distinctively marked (Pl. XI. fig. 14). Some of these cells 
(po) are seen to enlarge and protrude from the surface of the mesentery (msn) into the 
abdominal cavity as large primitive ova, and they occur, almost solely, slightly anterior 
to the urinary vesicle, especially above the region of the small intestine. In short, their 
appearance and distribution precisely accords with Batrour’s description of the early 
Elasmobranch ovum (No. 15, vol. xi. p. 161). The ova are most closely grouped on 
the roof of the abdominal cavity, and especially in the median niches formed by the 
projection of the suspensory septum or mesentery (msn). They are also grouped upon 
the mesentery, and some develop upon or have migrated to the peritoneal envelope of the 
intestine itself (hg). They are very irregularly distributed, and show great variation in 
size ; large spherical ova projecting from a mass of small undeveloped cells, and all 
loosely held together by the delicate connective tissue of the peritoneum. The ova 
appear to be like the cells adjacent, and differ only in their larger size and more active 
development. Each consists of a mass of minute nucleated spheres enclosed in a thin 
membrane ; but are quite unlike the primitive ova of Elasmobranchs, as described by 
Batrour (No. 13, p. 164), for these latter are uninucleate, one or two nucleoli, stain- 
ing deeply, occurring in the nucleus, which is large, and surrounded by a granular 
protoplasmic matrix. Along each side of this region of the abdomen, external to the 
abdominal cavity, a mass of cells may occur, not unlike, but less in dimensions than, the 
primitive ova described above. The lateral niche in which they are aggregated is defined 
by richly pigmented peritoneum, and this pair of lateral sacs strongly suggests the 
ovaries of the adult. The largest ova are those, however, which are free, and project 
boldly from the mesentery and roof of the abdomen. Ba.rour speaks of a thickened 
germinal epithelium in the Teleosteans, into which the adjacent stroma sends ingrowths— 
the cells of the epithelial layer increasing by the growth of the clear protoplasmic 
contents. But this does not correspond with the condition seen in the young haddock, 
each ovum being a more or less perfect sphere, and enclosing numerous minute 
nucleated bodies. Later stages were not observed, and it was not made out whether the 
lateral peritoneal sacs finally became the ovaries with their continuous genital ducts, or 
whether an epithelial layer grew over the freely suspended primitive ova, and enclosed 
them in an ovarian sac, depending from the abdominal roof. 
