260 



planted from Yellow River into Lake Maxinkuckee. On being examined 

 two years later in the autumn, when this species is usually gravid, it 

 was found to be sterile. 



The natural infection of fishes of the lake with the glochidia of 

 the mussels does not appear to be common. The gills of an immense 

 number of fishes were examined for parasites, but no glochidia were 

 noted. Some young bluegills and redeyes, exposed to the glochidia of 

 L. luteola in the autumn of 1912, took very readily. 



The young mussels were either few, or very difficult to find. Dili- 

 gent search was made for them, especially in the sandy bottom near 

 Long Point, the sand being scooped up and seived through fine-meshed 

 selves. Numerous and varied forms of life were thus obtained, such 

 as Sphaerium, Pisidinni, caddis cases, etc., and rather small but by no 

 means minute examples of L. luteola found. These young shells were 

 remarkably brightly rayed. Half-grown Q. rubiginosa were fairly com- 

 mon in the beds of Lost Lake. 



Proportion of Various Species in the Lake. — Of a collection of 340 

 living mussels collected October 17, 1907, at Long Point, 252 were 

 Lampsilis luteola, 41 L. ventricosa, 21 Unio gibbosus, 18 Anodo7ita 

 grandis footiana, 5 Strojihitus edentulus, and 3 Lampsilis subrostrata. 

 In deep water U. gibbosus and Anodonta would have given a higher pei"- 

 centage, and in the Lost Lake beds Quadrula viibiginosa would be present 

 in considerable relative abundance. 



Parasites, Enemies, and Diseases. — As a general rule the mussels 

 of lakes, ponds and bayous are more heavily infested with parasites 

 than those of the swiftly flowing rivers, the probable reason being that 

 in still waters the parasites can migrate more easily from one mussel 

 to another than where there is a swift current. The mussels of the 

 lake are not nearly so badly parasitized as those of the sloughs of the 

 Mississippi, the dead waters in the Maumee above the dams, or those 

 of the Twin Lakes a few miles to the north. The parasites will be 

 taken up more fully in consideration of the various species of mussels. 

 Several species of Atax, and Cotylaspis insignis are the most common 

 parasites. Unlike the mussels of most of our rivers, the mussels of the 

 lakes are comparatively exempt from destruction by man. A few are 

 killed and used for bait, and now and then a mild case of pearl fever 

 appears at the lake, but it is soon cu.red by the examination of a bushel 



