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Part III. — Tenth Annual Pvport 
largest of which had no less a diameter than 1*4097 mm., must have been 
exceptionally fine, and, moreover, well preserved. The large oil-globules, 
which had a diameter of from '2286 mm. to *2667 mm., appeared under 
the lens of a pale reddish-brown hue, but by transmitted, light of a pale 
red. In some a series of minute fatty granules were also present under 
the large globules, as indicated in the figure (PI. XV. fig. 8). No 
pelagic egg, with the exception of the sand-eel, has presented a more dis- 
tinctive colour. The zona is remarkably tough and resistant, and the 
fresh egg can only be ruptured by the exercise of considerable force. It 
presents on the surface of the entire egg (PI. XV. fig. 5) a series of boldly- 
marked punctures. In some views they have a slightly pinkish hue from 
refraction, and under a higher power (PI. XV. fig. 6) they give the cap- 
sule a minutely pustulose appearance. If a fragment of the zona be 
allowed to dry on a slide, each of the punctures enlarges, and becomes the 
centre of a curiously wrinkled margin, with numerous processes, such as 
would have been caused by a protoplasmic environment (PI. XV. fig. 7). 
In the present case, however, it was probably due to wrinkling of the dried 
zona. The latter, in the fresh example, is further marked by faint lines 
or creases, which in some are crossed by another series of lines or creases, 
so that the appearance is similar to that in the zona of the brill, lemon- 
dab, and sail-fiuke. The micropyle is very evident, and after the plan 
of that in the egg of the haddock ; the external aperture, which is in 
the centre of a depression, is smaller than the internal. 
The stage which the eggs had reached on arrival (4th day) is shown in 
PI. XV. fig. 8, the blastopore closing, or closed, the optic vesicles formed, 
and a broad alar expansion extending on each side. A small perivitelline 
space is present. Development proceeded normally, so that two days 
later (27th May) a number of myotomes were formed posteriorly ; a con- 
siderable portion of the tail was free, the pectoral folds formed ; lenses, 
otocysts, and a heart in which slight contractions were visible (PI. XV. 
fig. 9). Moreover, a few simple pigment-specks are scattered over the free 
portion of the tail. The embryo jerks body and tail. All the ova lie on 
the bottom of the vessel. 
Next day (28th) the eggs had made considerable progress (PI. XV. 
fig. 10). Black chromatophores are studded along the sides of the body 
and on the head, and some of these are slightly stellate on the head and 
near the pectorals. The heart has its open end as usual to the left and 
in full action. Each otocyst has two otoliths. The pectorals project out- 
ward as rounded lobes. In the specimen figured a peculiar conical cutane- 
ous knob projects outward from the head in front of the otocysts. The 
tail is much elongated, and has a group of black chromatophores at the 
tip. The perivitelline space is larger. 
Before hatching, a greenish-yellow hue (by transmitted light) appeared 
on the head and on the tip of the tail, as indicated in PI. XV. fig. 11. 
None were hatched on the 29th, but on the 30th May, at 11 a.m., that 
is on the 9th day, some emerged. The larva measures about 4 mm. in 
length (PI. XV. fig. 12), and is characterised by the large pinkish-brown 
oil-globule which is generally fixed at the posterior border of the yolk as 
in the figure. In some, however, the oil-globule is freely movable, a 
feature, in such larval forms, which has hitherto escaped me. By depress- 
ing the tail of the larva, the oil-globule glides forward to the middle of the 
yolk, and by elevating the head it mounts to the highest point, viz., the 
anterior border of the yolk. Nothing, indeed, could better illustrate the 
features formerly pointed out in regard to the movement of the oil-globule 
in the gurnard,* and the passage of the brightly-coloured globule through 
the yolk (and not merely at the surface of the yolk as some imagine) was 
* Researches, p. 687. 
