206 
Experiments on the Rearing of Fish Larve in the 
Season of 1894. 
By 
J. T. Cunningham, M.A... 
Naturalist to the Association. 
Ir may be useful to put on record the following notes of renewed 
attempts to solve the difficult problem of rearing fish larvee. 
On January 23rd a large number of eggs were observed in one 
of the aquarium tanks which contained several whitnmg. The eggs 
were collected and placed in a hatching jar, and began to hatch on 
January 29th. I prepared a small tank in the Laboratory for rearing 
the larva. The outflow pipe was protected by placing over it an 
inverted hatching-jar, open at both ends and resting on a layer of 
sand and gravel. The water was suppled to the tank by a solid 
carbon block filter attached to one of the jets. ‘The inflow of water 
was very slow indeed. The temperature in the tank on February 
8rd was 12° C., and on this date the larve in the tank were 
healthy, having the jaws developed, but the yolk not yet all ab- 
sorbed. One lot of larvee were put into the tank on January 30th, a 
second lot on February Ist. On February 4th I put in some fine 
particles of worm food, that is to say, ovarian eggs of Nereis obtained 
by mincing the worms and then separating the eggs by decantation. 
On the 5th, as the larve did not seem to take the worm-food 
readily, I put in some tow-net collections strained through fine bolt- 
ting cloth so as to exclude the larger animals. Then I saw the 
larvee pecking at this food, and in one I took out I found (in the 
stomach) a Gasteropod larva with spiral shell. On the 6th I put in 
a little of both kinds of food, and observed that the larve preferred 
the pelagic material, but they did not feed vigorously on either 
kind. On the 7th I examined a few, and found the stomachs of 
most of them empty and dilated, but in one was a small Copepod. 
On the 8th the number of the larve was diminished; on the 9th 
very few were to be seen, and on the 10th none were found. In 
the course of this experiment I found that when the supply of 
water was very much reduced on account of the choking of the char- 
