DESTRUCTION OF FISH. 101 
would serve not only as reservoirs to retain the water of winter 
rains and snow, and give it out in the dry season for irrigation, 
but as breeding ponds for fish, and would thus, without further 
cost, yield a larger supply of human food than can at present 
be obtained from them even at a great expenditure of capital 
and labor in agricultural operations.* The additions which 
might be made to the nutriment of the civilized world by a 
judicious administration of the resources of the waters, would 
allow some restriction of the amount of soil at present em- 
ployed for agricultural purposes, and a corresponding extension 
of the area of the forest, and would thus facilitate a return to 
primitive geographical arrangements which it is important par- 
tially to restore. 
Destruction of ish. 
The inhabitants of the waters seem comparatively secure from 
human pursuit or interference by the inaccessibility of their 
retreats, and by our ignorance of their habits—a natural result 
of the difficulty of observing the ways of creatures living in a 
medium in which we cannot exist. Human agency has, never- 
theless, both directly and incidentally, produced great changes 
in the population of the sea, the lakes, and the rivers, and if 
the effects of such revolutions in aquatic life are apparently of 
small importance in general geography, they are still not wholly 
inappreciable. The great dimiuution in the abundance of the 
larger fish employed for food or pursued for products useful 
in the arts is familiar, and when we consider how the vegeta- 
ble and animal life on which they feed must be effected by the 
reduction of their numbers, it is easy to see that their destruc- 
tion may involve considerable modifications in many of the 
material arrangements of nature. The whale + does not appear 
to have been an object of pursuit by the ancients, for any pur- 
* See AckERHOF, Die Nutzung der Sciche und Gewiisser. Quedlinburg, 1869. 
+ I use whale not in a technical sense, but as a generic term for all the 
large inhabitants of the sea popularly grouped under that name. 
The Greek x«jros and the Latin Balena, though sometimes, especially in 
