AQUATIC PLANTS IN" POND CULTURE. 5 



tical fish-culturists. They are presented, moreover, as pertaining 

 only to the particular field of pond culture conducted by the bureau. 

 Their application beyond this is yet to be determined. 



It may be assumed that all aquatic plants harbor a certain amount 

 of minute animal life. In the following descriptions, therefore, the 

 term " food producer " is applied to jjlants conspicuous for the large 

 quantity of small animal forms living or breeding thereon. The 

 term " oxygenator "' is applied to plants believed to be especially use- 

 ful in keeping Avater in a proper condition by throwing off oxygen. 

 The word "shelter" is applied to plants that afford the small fish 

 a hiding place and protection from the large ones and serve as an 

 aid to the prevention of cannibalism among the fishes. The term 

 " ornamental " is used to designate those plants that extend above the 

 surface and beautify the ponds. The depth of water in which the 

 plants are found as here mentioned applies to the ponds of the 

 respective stations in question. It is recognized that some of the 

 plants thrive in much deeper ponds and lakes. In most instances the 

 I^lants described under the various station heads are indigenous, hav- 

 ing appeared voluntarily. There are no records to show to what ex- 

 tent plants have been introduced, but undoubtedly some of the more 

 desirable j)lants have been introduced, largely through transfer from 

 one station to another. 



Common names of the plants are given, but as these are often of 

 restricted local application the botanical nomenclature also is used, 

 and for more ready identification figures have been inserted for 

 almost every species. All but one of the cuts are copied from Britton 

 and Brown's Illustrated Flora of North America. The figure of 

 Chara is taken from the Text Book of Botany by Strasburger, Noll, 

 Schenk, and Schimper. The geographical range of the respec- 

 tive species likewise is taken from these authorities. 



For the identification of a large number of these plants the bureau 

 is indebted to Messrs. J. N. Kose and G. H. Shull, of the United 

 States National Herbarium, Smithsonian Institution, and also to 

 the division of botany. Department of Agriculture. 



COLD SPRINGS, GA. 



At this station the water supply comes from a large spring, and the 

 maximum water temperature is about 82° F. The water contains 

 only a trace of lime, and . as a result some difficulty has been ex- 

 perienced in stocking the ponds with aquatic plants, but efforts in 

 tliis direction have resulted as follows, as reported by a former super- 

 intendent : 



For ponds with fairly fertile bottoms with an admixture of muck 

 and clay, the foxtail {MyrioyhyUuTn spicatuTri) excels all other 

 species. It makes an ideal gi^owth, affords abundant cover for the 

 fish and for the minute life upon which the fish feed, and is appar- 

 ently a good oxygenator. At the same time it offers but little ob- 

 struction to seining operations owing to its slender, feathery growth. 

 Even for ponds having rich muck bottom it has been found most 

 satisfactory, though in such ponds considerable work is required to 

 remove it when preparing for seining. 



For ponds with sterile bottoms of clay, sand, or gravel, where fox- 

 tail will not thrive, parrot-feather {Myrio'phyllum proserpiTiacoides) 



