HERTFORD SHIRE NATURAL HISTORY SOCIETY. 
xliii 
quantity of such eggs died, or from some cause did not undergo 
development. This was partly owing to their being subject to 
that very real fact, the struggle for existence, which goes on 
amongst ourselves as it does amongst the lower animals. The eggs 
of fishes had been proved to he deposited in one of two situations, 
either laid on rocks or sand at the bottom of the sea, or shed in 
the water, when they rise, owing to their lightness, to the top. 
But when they examined a quantity of the surface-water of the 
'sea, they would find that, although they came across a good many 
eggs of fish, there were also countless hordes of other organisms, 
which struggled for survival, sometimes indirectly, in taking up 
room, sometimes directly, in devouring the eggs, and he would 
show, by means of the slides, the eggs and pelagic organisms 
to be found on the shores of this country. The first of these shown 
was the embryo of the common sole, the next, the young sole in a 
further stage of development. At this stage both eyes were on one 
side, and the fish was coloured on one side and pure white on the 
other. The coloured side was generally called the back of the sole, 
though that was not the fact. The eyes, moreover, shifted their 
position during growth, until the curious distortion occurred. The 
younger stage of the pilchard was next shown, with its globule of 
oil, which enables it to float upon the surface ; and then the corre¬ 
sponding stage of the mackerel with its very large oil-globule, the 
size of this agreeing with the oily nature of the fish. Then came 
the angler-fish, which hides in the sand, throwing out its tentacles 
to excite the curiosity of other fish, which become its prey. This 
was one of the greatest enemies our food-fishes had to contend with, 
and although it was eaten, it was said not to be very good food. 
Various stages in the development of our food-fishes were then 
illustrated and spoken of; and then the creatures which form a 
very large portion of the food of whales. Amongst these, crus¬ 
taceans were shown, which served as food for many fishes. The 
spines which many of these bear might be supposed to be for their 
protection, but when shoals of herrings or mackerel came along, 
they did not stop to enquire, and did not even object to canni¬ 
balism. The spines, while they did not secure immunity to the 
possessor, often caused the death of its devourer, because they 
produce inflammation of the alimentary canal. The young of all 
these creatures were absolutely transparent, so that the sea seemed 
to be devoid of life ; but if they got some sea-water in a pan and 
strained it, they would get a gelatinous mass, which consisted of 
the bodies of these creatures. The extreme transparency was said 
to be produced in order that they might be invisible to their foes, 
most of them being related to creatures at the bottom of the sea 
which are brightly coloured. But when they considered that their 
foes were mostly whales and other pelagic fish, it was difficult to 
believe that this transparency was an advantage to them at all. 
The whale fills its mouth with gallon after gallon of water, which 
it strains, swallowing the solid residuum. Therefore of that fact 
they had no adequate explanation. 
