EXPERIMENTS IN THE ARTIFICIAL PROPAGATION 
OF FRESH-WATER MUSSELS. 
ed 
By GEORGE LEFEVRE and W. C. CURTIS, 
Professors of Zoology, University of Missourt. 
a 
OBJECT AND SCOPE OF THE UNDERTAKING. 
The threatened extinction in the Mississippi River and its more important 
tributaries of those species of mussels whose shells have been taken in enormous 
numbers during the past fifteen years for the manufacture of pearl buttons has led 
the United States Bureau of Fisheries to undertake an extensive investigation 
to determine the possibility of artificial propagation of these mollusks, and to 
devise such means as may be practicable for restocking depleted waters which 
present favorable conditions. The general direction of the investigation has 
been placed in the hands of the writers, who for the past three years have 
devoted to the work as much time as their professional duties would allow. 
In certain phases of the work, however, many others have collaborated. 
It was recognized at the outset that if the investigation was to have real 
practical value it would have to be wide in scope and extend over a period of 
at least several years. At that time little was known with accuracy of the 
breeding habits and seasons of the commercial species, of the biological and 
physical conditions under which they live, of their distribution, and of many 
other essential matters, while it yet remained to be discovered whether artificial 
propagation could be successfully accomplished. At the very inception of the 
work, therefore,“a comprehensive plan was outlined which was designed to 
include every subject that might bear even remotely upon the central problem, 
and, although many parts of this programme have not yet been touched, much 
progress has been made in some of the more important lines. 
The plan of work contemplated, besides a thorough investigation of artificial 
propagation, a detailed study of the life history and ecology of the Unionide, 
emphasizing especially the geographical distribution of the group throughout the 
Mississippi Valley, the breeding habits and seasons, the physical conditions of 
the waters in which the different species thrive, food, enemies, and diseases, 
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