6 



MUSSEL FAUNA OF THE KANiKAKEE BASIN. 



In Indiana, however, the entire basin of the Kankakee River is 

 marshland, the most extensive body of swamps within the State. 

 On the immediate border of the river there is a strip^ from a few 

 rods to a mile or more in width, which is heavily timbered. Then 

 come dense thickets of underbrush, and finally the open marsh, 

 covered with a rank growth of grasses, sedges, reeds, and semi- 

 aquatic vegetation. 



There Avere formerly more than half a million acres of this marsh- 

 land in the seven Indiana counties drained by the Kankakee, but its 

 area has been recently somewhat reduced by extensive ditching. 

 Enough still remains, however, of this old glacial lake bed to act 

 in the manner of an immense sponge, overflowing and absorbing 

 water during the wet season and slowly oozing it forth during 

 the dry. 



There is thus never any real lack of water in the river, the amount 

 of discharge at the State line being considerably over a thousand 

 cubic feet per second even at low water. In general the soil of the 

 marshes is a dark sandy loam, very rich in organic matter, and 

 hence the waters of the river contain an abundance of food material 

 for the mussels they contain. In many places the wild rice, rushes, 

 lily pads, and aquatic grasses fill all except the very channel of the 

 river and contribute their quota of food material. Owing to the 

 fact that the land can not be cultivated, there are few dwellings on 

 or near the river, and repeatedly one may row 15 or 20 miles without 

 seeing a human habitation. The presence of the rich marshes, com- 

 bined with the absence of human environment, have made this 

 region an ideal breeding ground for waterfowl and aquatic animals 

 of every sort. Fish are also abundant in the river, together with 

 plankton of great variety and richness. Each and all of these con- 

 ditions have a very important bearing upon mussel life. 



And withal the region is one of marvelous beauty and attractive- 

 ness, and as radically different in many respects from an ordinary 

 swamp as could well be imagined. In the first place, the river itself, 

 in spite of its intricate windings and rich vegetation, is not sluggish 

 as one would expect, but has everywhere a good current, averaging 

 3 or 4 miles an hour. Then the river bed is nowhere of the pro- 

 verbial quagmire type, but is hard sand or fine gravel, mixed with 

 mud to just the right consistency for most mussels. Here, then, we 

 have a region especially favorable in almost every particular for 

 mussel growth, strictly secluded by its environment from all but the 

 hunter, the trapper, and the fisherman, and still maintaining primi- 

 tive conditions throughout most of its extent. Futhermore, its 

 waters have always drained into the Mississippi Basin as they do 

 now, and the mussel fauna, originally derived from that source, has 

 never undergone any radical changes. 



