130 THE CANADIAN NATURALIST. [-^P^ilj 



all the inconveniences of bringing the eggs where you cannot see 

 them, and cannot watch their progress. 



There are two kinds of hatching-apparatus, which may be used ; 

 — one out of doors, for carrying out operations on a large scale ; and 

 the other for use on a smaller scale in-doors. 



I far prefer the in-door apparatus, which is very simple in con- 

 struction, more certain of success, cleaner, neater, and at the same 

 time affords the great pleasure to the owner of being able to ob- 

 serve the progress of the eggs. The slate-boxes on the tables are 

 those used by my friend, Mr. Ponder, at Hampton, in which 

 he has hatched so many thousands of fish, paying for the 

 boxes out of his own pocket, and giving his time gratuitously 

 for the Thames Angling Preservation Society. They are three feet 

 long, and three and a half inches deep. They should be placed one 

 above the other, after the manner of the steps of a staircase, and so 

 arranged that the water runs through them all in zigzag m anner. 

 Some gravel, about the size of peas, must be obtained from a gravel 

 pit, not from the river-side. It must be well boiled to destroy all the 

 seeds of vegetation, be washed perfectly clean, and then placed in the 

 troughs, so that there should be an inch of gravel, an inch of water, 

 and an inch above the water. Place in the eggs, put on the wooden 

 covers, see that the stream runs properly, and leave them entirely 

 alone in the boxes. Such as these have this year, at Hampton, 

 hatched out, and are still hatching out no less than 124,700 

 fish and eggs. 



All that is requisite is a gentle and incessant flow of water, and 

 what is water enough for one trough is, as a matter of necessity, 

 enough for half-a-dozen or so. In London houses the supply of 

 water is often limited ; it is a comfort therefore to know that the 

 same water can be used again twice or three times. 



If you wish to hatch your fish in boxes out of doors, you must 

 adopt the same principle as that applied to in-door boxes, recollect- 

 ing the requisites, — a clear running stream, clean gravel, and dark- 

 ness. Full details of both in-door and out-door apparatus, and 

 also the proper mode of working them, can be found in my little 

 book.* 



The eggs having been placed in the boxes and left totally undis- 

 turbed, in course of time the eyes of the young fish will be seen 

 like two black spots in the egg. The time required for this ap- 

 pearance to exhibit itself depends entirely on the temperature. 



* Fish-hatching. Tinsley Brothers, Catherine Street, Strand. Price 5s. 



