56 THE FOSSIL SLOTH AT BIG BONE CAVE, TENN. [Jan. 15, 



Academy of Natural Sciences. If the whole combined series 

 fails to duplicate or contradict the construction of a single fossil 

 sloth skeleton, then all, because all indicate a young animal, and 

 because all show cartilage as no other sloth bones elsewhere 

 found have yet done, can be reasonably referred to the same indi- 

 vidual animal. Many other bones, originally near or upon the 

 surface, may have been removed by Indians or carried away by salt- 

 petre diggers and lost. Rats may have made off with others. And, 

 notwithstanding the fact that the sets belonging to the Academy 

 and Prof. Safford, together with my specimens, may fail to recon- 

 struct the animal's skeleton, the three sets together include enough 

 bones to indicate that the creature had once lain there in the 

 flesh. Because the tooth marks seem to refer to the work never of 

 carnivora, but always of rodents, less to the efforts of large than 

 of small animals not strong enough to have carried a skull 

 such as Priest found, or a scapula like that at the Academy, 

 from any other resting place in the cave, it seems reasonable to 

 suppose that the bones reached their position by the most natural 

 of agencies : that the sloth, lost or overcome by sickness in the dark- 

 ness, had lain down to die at the place in question. 



Reasonably doubting that it had shambled into the cave after the 

 helpless club-footed manner of the modern Ai or Unau, shall we 

 speculate further and imagine that the animal, less clumsy and slug- 

 gish than its modern South American relatives and presumably her- 

 bivorous from the structure of its teeth, was attracted to the spot by 

 the smell of grass and leaves, brought thither by porcupines and rats ? 

 If not, we must believe that its choice of a deathbed in the only rat 

 den in that part of the cave was a coincidence. But, however the 

 position of the bones is to be accounted for, let us believe that if the 

 carcass lay upon the manure, the number of visiting omnivorous 

 rodents increased until the process of devouring the flesh had been 

 succeeded by the gnawing of the bones. 



If these suggestions explain how the bones came to be where 

 we found them, we next ask. How old are they ? When 

 did they reach their position ? An inquiry above all de- 

 pending upon the study of the objects dug out of the earth 

 with them. These are to be divided into three classes : First, 

 objects of later age than the bones, or of doubtful antiquity ; 

 second, objects as old as the bones, and third, objects older than 

 the bones. To the first class belong the torch ends of cane. 



