1896.] on Fish Culture. 43 



In the tank are the bowls or dishes which are used in taking the 

 ova. The eggs are expressed into these dishes. The milt is ex- 

 pressed upon them, and the two mingled together, and after a while 

 they are washed, and the eggs laid down in the hatching boxes. In 

 order to have purity of water — I do not mean chemical purity, but 

 freedom from matter held in suspension — we have to use a system of 

 filtration, and one of the first processes is to filter the water as it 

 comes from the stream itself, and for a long time we had a great deal 

 of trouble in doing this, because the screens which we use choke up 

 and require a great deal of attention, and sometimes cause disaster 

 by being overlooked. We have now got a system which works for a 

 whole season without the slightest attention. Once j)ut it in order, 

 it regulates itself. If we imagine this model to represent the bed of 

 the stream — the sheet of perforated zinc here, and the stream flowing 

 through this box — you can see that the water passing through leaves 

 behind on the zinc anything in the shape of leaves and small pieces of 

 stick and other matters which are floating in it. We found that by 

 setting this at a certain angle if we had twice as much water flowing 

 over it as we had going through the zinc it never stopped ; and 

 so, applying this principle, we are able now to run the whole year 

 through without the slightest trouble. The water passes through the 

 zinc into the box, and passes out at the hole at the end, and is drawn 

 off to sujDply the hatchery. 



There is a tank house or place where the water is filtered. Here 

 we have some concrete tanks in which the water is allowed to settle. 

 They are settling tanks in fact. After settling, the water flows from 

 these tanks into a filter box, which is full of wooden screens covered 

 with flannel through which the water passes. This takes away any 

 sediment which may still remain, and the water comes out perfectly 

 pure, passing on into the hatchery. 



Having got the hatchery in order, we have to take the eggs from 

 the fish, and this is done first of all by netting tbem, and then sorting 

 the difterent kinds into difi'erent vessels, and taking them when they 

 are ripe; that is, when they are ready to yield their ova, and by 

 gentle pressure the eggs are quite easily stripped from them. In 

 America this is done with large fish, where a great many have to be 

 done, by putting them into a wooden box by which the head is locked 

 so that it cannot move, and the eggs are taken from it. In this way 

 a large number of fish, like salmon, can be manipulated in a very 

 short time. Here we have a sort of spawning tub. The fish have 

 been taken from a store pond, and are now in the net. Here are 

 the tubs and receptacles into which they are about to be put and then 

 sorted (Fig. 3). 



Another photograph will show the next process : a lot of fish being 

 taken and put into tubs. There are the spawning tubs all ready, and 

 the spawning table used in this operation is also shown. The eggs 

 are carried down to the hatcheries and laid down in the hatching boxes. 

 There they remain for a period of something like three months, the 



