46 FISH CULTURE 



as a possible diversion from their cannibalistic 

 instincts, and because it promotes growth. 



Every pond should be abundantly supplied 

 with such aquatic plants as are particularly 

 affected by such plankton as daphnia and cy- 

 clops, as it has been found that this food causes 

 a more rapid growth among the advanced fry 

 than any artificial food which can be given 

 them. The best aquatic plant for this purpose 

 is chara moss. The potamogeton is also rec- 

 ommended very highly, but it is not so satisfac- 

 tory as the chara moss, especially for small- 

 mouthed bass, which most fish-culturists now 

 try to rear, and which are the most difficult 

 with which to succeed. The chara moss forms 

 a thick mat over the bottom of the pond; so 

 thick, indeed, that unless frequently thinned 

 too great a quantity will form and smother the 

 young fish. It is most important that there 

 always be kept a clear space of water, about a 

 foot in width, on all sides of the ponds. 



By heavy feeding, both with natural and 

 artificial food, and with a favourable water-tem- 

 perature, smallmouth fry should be brought to 



