44 FISH CULTUEE. 



taking up a stone or two, and the use of a small glass 

 tube as a siphon, the eggs, and even the fry, can 

 always be drawn up into the tube with water, and 

 inspected without injury. It is no doubt a very 

 pretty sight to see the beautiful ova ranged thickly 

 on the surface ; but when a thick sediment covers 

 them, which you do not like to interfere with over 

 much, for fear of moving the ova too roughly (a 

 liberty which ova will not permit of), the sight is not 

 so cheerful ; but, if this sediment merely settles on the 

 upper face of the gravel stones, little or no harm is 

 done, as you can sweep it away boldly, if it becomes 

 too troublesome, without moving an egg or a stone. 

 The conferva generally settles and roots itself on the 

 upper face of a stone, preferring the light, and you 

 may take up a stone foul with slime on the upper face, 

 but bright as silver on the under side, and thereiu 

 lies the safety of your ova. The water will not 

 fail to find its way through the interstices ; and all 

 that the ova require is to be kept clean, cool, and 

 moist. 



A great deal of philosophy, much of which is some- 

 what imaginary, has been talked of the necessity for 

 a rapid stream, and the constant aeration of the water. 

 To exclude air altogether, or water altogether, would 

 of course be fatal; a good stout coat of mud, for 



