THE AMERICAN BISONS. 



133 



The fact that the reservoir of these waters is belo.w the general surface causes 

 them to appear in the bottom of the valleys, and the considerable abstrac- 

 tion of matter from the underlying beds, probably amounting to some hun- 

 dred cubic feet per annum in the case of Big Bone Lick, causes a depression 

 at the point of escape, and generally brings about the formation of a 

 swamp in a depressed and constantly lowering basin, through which the 

 spring water creeps away, or is evaporated. This swamp forms a natural 

 trap for all the higher mammalia of this region. When excavations are 

 made near the existing outlets of the springs, we find remains of the large 

 mammals brought into the country by man, — the horse, cow, pig, and sheep. 



A. Alluvial matter. b, Level where deposition of sediment is now taking 



B. Limestone. place. 



C. Calciferous sandstone. c, Present position of stream, 

 a, Oldest bone-bed as yet opeued. d, d. Springs in curbs or " gums " rising some feet 



above the surface. 



Diagrammatic Section of the beds at Big Bone Lick. 



In the frequent change of outlet of these springs, it comes to pass that at 

 many points near the surface of the thirty or forty acres that lie in the little 

 basin where Big Bone Lick is found, there are old spring vents, about which 

 bones are found, that no longer give forth saline waters. It is a fact bearing 

 on the history of the buffalo, that their remains about Big Bone Lick are, 

 when found, always near the present position of the springs and never at any 

 depth beneath the surface. In the recent springs they are very abundant, 

 and not much more ancient in their appearance than the remains of the 

 domesticated animals. The evidence obtained at this point leads to the con- 

 clusion that the first appearance of this species in the country was singu- 

 larly recent, and also shows that their coming was like an irruption in its 

 suddenness. These buffalo bones are wonderfully abundant in some of the 

 shallow swampy places of this neighborhood. I have seen them massed to 



