DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 675 
fic. 23). This species seems to spawn from January (or perhaps even from December) 
to April. 
Cottus scorpius (Pl. I. fig. 3).—The ova present various shades of red, inclining at 
times to orange or yellow.. Their diameter averages ‘075 inch, and the large oil-globule 
ranges from ‘015 inch in diameter downward. The zona is smooth, except where the facets 
for attachment to adjacent ova occur. Minute dots are visible under a high power, and 
these have a more regular linear arrangement, as a rule, than in Cyclopterus. Moreover, 
larger dots occur at intervals all over the surface, recalling those noted in Cyclopterus 
taken from the stomach of young cod. In the Report to H.M. Trawling Commission,* 
one of us has alluded to the error of Professor ALEXANDER AGaAssIz in considering the 
ova of Cottus pelagic, a fact overlooked by Mr Cunnincuam.t 
Ammodytes tobianus, L.—G. O. Sars states that the comparatively large ova of this 
species are not pelagic, but are laid in loose sand, where they go through their 
development. Covcn, again (No. 44, ill. p. 138), considered that it sheds its ova 
in this country as it dashes through the sand in December; while Day (No. 51, i. 
p- 333) found the reproductive organs in both male and female, at St Ives, far 
advanced in August and September. On the other hand, THompson states that in 
Ireland they were nearly ripe at the end of July. The organs, however, were found 
to be small in November at St Andrews. Early in May some specimens (none more 
than 6 inches in length) showed ripe spermatozoa, though the testes were comparatively 
small; while in the females the ovaries were not much developed, and contained 
very minute eggs. These eggs were transparent and granular, with a large germinal 
vesicle. Some larger eggs, five or six times the diameter of the remainder, showed 
a coarsely granular yolk, with many small oil-globules, and a very thin external 
capsule, which is finely reticulated, and provided with minute punctures as in other forms. 
In the ovary the eggs appear to have a somewhat whorled arrangement. Later, about the 
beginning of June, the reproductive organs in about twenty examples showed an irregular 
state of advancement, some having fairly advanced ovaries, while others were rudimen- 
tary. In those best developed the ova were of a rich orange colour, “reddish yellow,” as 
Sars said, and they were just visible to the naked eye as minute grains ;); of an inch in 
diameter. The germinal vesicle was still very evident, measuring 3}9 inch. Most of 
the larger ova were of this size, though others were much smaller, the smallest being in 
fact less than the nucleus of the largest eggs, and their nuclei showed many nucleoli. The 
zona is distinctly dotted at this stage. The sperms in the male fishes showed a distinct 
head, but no motion was visible at this time. So far as could be observed at St Andrews, 
the spawning period of this species would seem to be late, indeed so late as to bring it 
within a reasonable distance of the pelagic larval forms described in a subsequent 
chapter.{ In some examples, however, examined in the middle of December, the genital 
* 1884, + Op. cit., p. 103. 
t Section xi. Investigations, at present being carried out by Mr W. L. CatpEerwoop at the St Andrews Labora- 
tory, may clear up the subject. 
