AQUATIC PLANTS IN POND CULTUEE. 



21 



each, but since the lilies have taken the place of all other plants the 

 annual production has dwindled to less than 2,000 fish to a pond. 

 Mr. Seagle is therefore forced to the conclusion that the water-lily is 

 a dangerous plant, especially in ponds having soft fertile bottoms, 

 and that without the submerged plants successful bass culture is 

 impossible. By con- 

 trast Cliara^ with 

 its merit of being 

 an excellent food 

 producer, comes 

 into better esteem 

 in spite of its ob- 

 jectionable quali- 

 ties. 



NORTHVILLE, MICH. 



At the North- 

 ville, Mich., station 

 pond culture is a 

 new feature, the 

 ponds having been 

 completed but four 

 years. Vegetation 

 in the form of 

 Chcira took pos- 

 session of them al- 

 most immediately. A few other plants have obtained a foothold, 

 but not in appreciable quantities. The ponds are devoted to the pro- 

 duction of small-mouthed black bass, and the results have been quite 

 successful. The superintendent, Mr. Frank N. Clark, states that he 

 knows of no other plant than Chara so productive of fish food of 

 the sort acceptable to the young bass, and the objectionable characters 

 of the plant do not in his opinion offset its merits. 



Fig 26. — Sweet-scented white water-lily {Castalia odorata). 

 Found in ponds and slow streams. Nova Scotia to Manitoba, 

 south to Florida and Louisiana. (After Britton & Brown.) 



MAMMOTH SPRING, ARK. 



At the Mammoth Spring, Ark., station, established in 1905, a por- 

 tion of the bottoms of three ponds is composed of a heavy muck — the 

 remains of an old swamp bed — and in these portions there immedi- 

 ately sprang up Chara^ Elodea^ Ranunculus aquatilis, C eratophyllum^ 

 Myriophyllum, and Potamogeton^ the relative abundance of each 

 being in about the order named. The entirely new ponds and those 

 parts of the others newly excavated are of a clay and gravel mixture. 

 It appears from the report of the superintendent, Mr. M. F. Staple- 



