22 



AQUATIC PLANTS IN POND CULTURE. 



ton, that an attempt was made the first two seasons to establish 

 Ranunculus aquatilis and Elodea in these latter, but they were 

 crowded out by Cliara^ and Chara has since then sprung up volun- 

 taril}^, with results in all ways satisfactory. The superintendent has 

 no preference for any particular plants. They are now quite gen- 

 erally mixed and all are rank in growth. It is his intention to intro- 

 duce Chara in a jjroposed new pond, because this plant will flourish 

 on a poorer soil than the other kinds. 



At this station, on April 30, 1908, a pond 18,000 feet in area was 

 stocked with 20,000 (actual count) small-mouth black bass fry. On 



June 24, eight weeks later, there 

 were removed from this pond 6,000 

 fingerlings, ranging in length from 

 3 to 4 inches. The rapid growth 

 and large number of fingerlings 

 reared is attributed to the presence 

 of exceptional quantities of small 

 amphipod crustaceans {Gamma- 

 rus), which are a valuable fish 

 food : and the abundance of this 

 food, while attributable to the qual- 

 ity of the water, seems to be de- 

 pendent also upon the presence 

 and character of the aquatic vege- 

 tation. 



SAN MARCOS, TEX. 



At the San Marcos, Tex., station 

 one of the milfoils, Myriophyllum 

 heterophyllum^ is preferred to all 

 other water plants. Mr. John L. 

 Lear3^ the superintendent, states 

 that here some of the water-lilies, 

 Chara^ and the cattail {Typha 

 latifolia) will, if permitted, crowd 

 out all other plants of value, and he regards frogsbit {Rhizodomum 

 horsfordi)^ because of its exuberant growth, as the most objec- 

 tionable of all the plants found in the pond. He believes water 

 plants essential in pond culture, but suggests that ponds be con- 

 structed with sand and gravel bottoms with the view to keeping them 

 free of all aquatic vegetation, except in selected places where the 

 plants are to be walled in with concrete, the walled-in portions to be 

 filled in with earth of the richness required by the plants selected. 



At the Mill Creek station of the Michigan Fish Commission for the 

 propagation of both large-mouth and small-mouth black bass Chara 



Fig. 27. — White water-crow foot {Ra- 

 nunculus aquatilis). In ponds and 

 streams, Nova Scotia to British Colum- 

 bia, south to Norta Carolina and Cali- 

 fornia. Also in Europe and Asia. 

 (After Britton & Brown.) 



