842 PROFESSOR W. C. MSINTOSH AND MR E. E. PRINCE ON 
bring out this feature, since the temperature was thus proportionally high. Moreover, 
as indicated in the Report of the Royal Commission on Trawling just mentioned, with 
reference to Hippoglossoides limandoides (Rough Dab) and other species, comparatively 
small specimens of both sexes are capable of successful reproduction. Thus females not 
more than 44 inches long, and males a little larger (74 inches), have been paired with 
perfect success. 
Ova fertilised at 4 p.m. on Ist April 1886, showed a wrinkled condition of the zona 
radiata after extrusion, but soon became smooth in outline, and the germinal cap or 
blastodise began to be formed. In some, however, no such protoplasmic cap appeared 
for an hour or more. The two-celled stage was reached at 6 p.M., and the sixteen-celled 
stage at 9.45 pM. The minute granules of the periblast were very evident in a profile 
view. In these ova the micropyle was generally found near the disc. Next morning 
(9 a.m. April 6) the blastoderm had made great progress, and the cells were nearly of 
equal size. At 1 P.M. it had extended almost as far as the equator. At 9 P.M. a large 
germinal cavity had appeared. On focussing down to the animal pole (the egg floating 
with the dise downward in the usual manner), a peculiar group of cells was visible, 
probably at the apex of the blastodermic cap, since the ordinary cells of the 
germ lay above them. Moreover, the two ova specially under examination presented 
certain (BRownraNn?) movements of the granules of the region, as if from decay, 
yet such could not have been the case, as subsequent progress proved. On the 
7th, at 9 a.m., the embryo appeared in the centre of the embryonic shield, as 
a long curved cylinder with an expanded and thickened head. It is proportionally 
longer than in round fishes, such as Gadus morrhua, G. exglefinus, and others. The 
more distinct than in 

cells of the blastoderm assume a honey-comb-like appearance 
many Teleosteans. On the evening of the same day (the 7th) the optic vesicles are 
well developed, and the tail shows a more evident enlargement in front of the tip 
than in Gadus exglefinus. Kuprrer’s vesicle is present, while in many examples four 
or five smaller vesicles exist on the ventral surface of the caudal enlargement. On 
the 8th April, the vesicle referred to is larger, and situated just within the blunt knob 
of the tail. It is a large clear bubble-like vesicle, bounded by slightly granular proto- 
plasm (periblast) of variable thickness. The yellowish pigment, characteristic of this 
species, now appears in the form of rounded corpuscles (Pl. XIX. fig. 5), which do not as 
yet send out radial processes. Occasionally one or two clear vesicles occur under the head, 
and they have the same appearance as Kuprrer’s structures. No other organs, except 
muscle-plates and neurochord, are visible in the trunk. On issuing from the egg the 
larvee (Pl. XIX. fig. 5) float on the surface if lively, but if feeble they rest on the 
bottom in still water, 7.e., in the tanks, though it is probable that this latter phenomenon 
does not occur in nature. They shoot with a wriggling motion along the surface, and 
are recognised by the beautiful yellow grains of pigment; they appear, in fact, like minute 
clubs of transparent tissue with chrome-yellow spots. One evident patch of colour 
lies above the posterior end of the yolk, and another midway between that point and 
