THE POTAMOGETONS IN RELATION TO POND CULTURE. 



By EMMEUNE MOORE, 

 Contribulion from the Department of Limnology, Cornell University. 



J- 

 INTRODUCTION. 



The cultivation of lakes, ponds, and streams follows as a natural consequence the 

 biological investigation of the aquatic life within them. Herbivores and carnivores 

 live their life in the water, and if we ponder over their means of sustenance we are 

 struck by the fact that the natural food supply has rarely been augmented by cultural 

 methods. 



"The larger aquatic plants," says Pond (1903), "form a link in the chain of nutri- 

 tive relations that stretches from the water and soil to the higher fishes." If such is the 

 importance of these plants, the great mass of vegetation which comes to maturity each 

 season is a national asset. Yet the annual yield has never been estimated or given a 

 place in the Government crop reports. 



Aquatic plants have contested for possession of the waters much as the grasses 

 have contended for supremacy on land, until it may be said that the dominant forage 

 crop of our lakes, ponds, and streams is to be found among the pondweeds, the Pota- 

 mogetons. Variety in form, adaptability to environment, and diversity in range have 

 all contributed their share in giving prominence to this group and in furthering a natu- 

 ral resource whose propagation and control are vital factors in the economic relations 

 of the life of inland waters. 



The object of this investigation is to present such observations and experiments 

 on the natural and artificial propagation of the Potamogetons as will render cultural 

 methods economical and practical. 



The work herein recorded was carried on at Cornell University under the direction 

 of Dr. James G. Needham, to whom I wish to express mv grateful thanks for help and 

 suggestion. 



HISTORICAL. 



The cultivation of aquatic plants was an ancient occupation, one which concerned 

 itself with the beautification of pools and fountains. In modern times, too, aquatic 

 plants have been used in variety and profusion in the ornamentation of artificial or 

 natural ponds. But the cultivation of aquatics from an economic standpoint is a new 

 idea, so new, in fact, that data regarding it are just beginning to appear in bulletin 

 form in the Government compilations of scattered and isolated experiments. In the 

 bulletins plants of the genus Potamogeton have received the larger measure of notice 

 because observations on the feeding habits of animals associated with them point to 

 the important role of these plants in the economy of nature. 



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