FOE PLEASURE AND PROFIT. 77 



outlet awaiting the food that is brought down, and the other- 

 wise enriched water that is found there. 



Valuable as watercress is in fish-culture operations, it is 

 not all-sufficient, if only for the reason thait it will not grow in 

 deep water. Moreover, we must not overlook the fact that 

 in some cases it cannot be grown at all, although these- ] attcr 

 are, fortunately, very few and far between. In my estimation, 

 the plant that ranks next to watercress in importance is lake- 

 wort (Littorella lacustris), and where the two can be estab- 

 lished in conjunction your stock of natural food for young 

 fish especially is pretty well assured. Lakewort fills the gap 

 left by watercress, inasmuch as it is admirably adapted 

 for the bottoms of ponds or lakes. It ranges in 

 height of growth from two inches to four or five inches : 

 in exceptional cases I have seen it as high as seven 

 or eight inches, never more. The free growth of lake- 

 wort ensures an enormous supply of small mollusca and 

 valuable animalculse, and, in common with watercress, it never 

 becomes a nuisance from overgrowth. It is ai good tip to 

 establish lakewort in your ponds before staiting to fill them 

 with water, and afterwards to replant patches of the bottom 

 that may, perhaps, become bare Once established, only ordi- 

 nary care is required to ensure a permanent covering for the 

 bottom of your ponds. 



Other suitable plants to encourage the increase of molluscai, 

 Crustacea, and numerous animalcules are : Water lobelia 

 (Lobelia dortmanna), Marsh marigold (Calihapalustris), water 

 plantain (Alisma plantago), dwarf spearwort (Ranunculus 

 flairnmula), starwort (Chara flexilis), and water moss ^Fonti- 

 nalis antipyretica). Of these, water lobelia will sometimes 

 flourish where lakewort will not, and vice versa. They are 

 very similar plants in growth, only that lobelia flowers and may 

 be established by means of seed. If both do well in your 

 water, so much the better. The marsh marigold is suitable 

 only for the edges of ponds and for shallow waters. It is a 

 capital plant for artificial and natural redds and for any waters 

 in which very young fish are being reared. In, some cases 



