[7] ARTIFICIAL PROPAGATION OF FISH. 497 
apparatus especially prepared for this object or in a tank or basin hay- 
ing the desired conditions of safety and temperature. 
Natural spawning places may suffice for everything which has been 
recommended in the above. 
§ 4.— Artificial spawning places. 
As has been indicated at the end of the last paragraph, the simplest 
means of multiplying those species of fish whose eggs adhere to foreign 
bodies is to make the fish deposit their eggs in a place provided for 
them in a pond or water-course, &c. This may be done by means of 
very simple and inexpensive apparatus which are generally composed of 
wooden frames (Fig. 5) of different shapes and sizes, covered with aquatic 
Fic. 5. Fic. 6. ° 
plants, brush-wood, &c., arranged in such a manner as to resemble a 
small roof for sheltering things (Fig. 6). Their size, which varies from 
1 to 2 meters, their distribution and position, of course, depend on the 
different localities. It is always 
necessary that one end of the ap- 
paratus should be weighed down 
by a sufficiently heavy weight to 
apparatus under the water (Fig. 7). 
One or two months before the 
Fic. 7. presumed time of spawning, these 
apparatus are placed on the banks of the water where the fish live, and 
are taken out again after spawning is over. The bunches of herbs are 
then carefully taken off, and are, in order to insure the hatching, placed 
under the same conditions as the products of artificial fecundation. 
For those fish which deposit their eggs free on the gravel, or hide them 
in the spaces between the stones, as is the habit of the salmonoids, it 
will be best to select brooks with clear and not very deep water, and 
S. Mis. 29-———32 
