72 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
fossil of the valley of the Saint Lawrence and of certain portions of 
Northern Europe. 
The occurrence of fossil fish in immense numbers in certain geologi- 
cal formations has been a subject of much interest to the geologist and 
naturalist, and many hypotheses have been promulgated in explanation 
thereof. It is not at all probable that the ordinary casualties happen- 
ing to fish would produce anything like the phenomena in question. 
It is believed that very few fish die of old age, the incidents of life in 
the sea being such that whenever any animal loses the ability to care 
for itself some enemy is ready to devour it. The accumulations referred 
to, found at Monte Bolea in Sicily, in Syria, in many parts of the 
United States, and elsewhere, probably result either from some mys- 
terious disease attacking the fish in large bodies, or from some physical 
cause. There is but little evidence to prove the existence of serious 
epidemics among fish in the sea, although such an occurrence is not at 
all improbable. Even here, however, it is likely that there would be 
enough scavengers to devour the dead and dying almost as rapidly as 
they succumbed to the baleful influence. 
One of the methods by which fish are destroyed in great quantities, 
and yet kept in a condition favoring their ultimate preservation, as in 
rock strata, consists in the sweeping of large schools, during storms, 
into low, shallow basins at the edge of the sea, where, of course, death . 
will very soonensue. The gradual concentration, however, of the water 
by subsequent evaporation, answers the purpose of a slow and careful 
salting of the fish, so that for a considerable time after the basin is 
dry the fish remain in a good state of preservation. If, as is probably 
often the case, sand and mud are swept in with the fish, and this is 
repeated at short intervals, a succession of strata with skeletons of 
fish and other marine objects may result. 
A case of this kind has been mentioned to me by Lieut. Z. L. Tanner, 
U. 8. N., who noted the phenomena during the cruise of the United 
States steamer Narragansett in 1872, at Christmas Island. The surface 
of the shallow basin inside of the beach was occupied by many hun- 
dreds and even thousands of fish, varying in length from a few inches 
to three or four feet, and preserved in perfectly good condition, the thor- 
Oughly cured flesh being, however, too strongly salted to be palatable. 
TV.—TuHE NATURAL FOOD OF SEA FISH. 
The vegetable kingdom at sea, as well as on land, constitutes the 
starting point of all animal life, and whatever may be the extent to 
which animals devour their fellows, whether as adults, embryos, or eggs, 
there is no doubt that without the presence of plants in some form or 
other and their assimilation, the existence of animal lifein the sea would 
be an impossibility. It is less easy, however, in the water than on the 
land to see the connection between the two kingdoms in this respect, | 
espeeially as the most important element of the vegetable division is in 

