994 The American Naturalist. [ December, 
when we reinvest this continent with herds of wild animals, 
gregarious in habit, and probably reaching a great numerical 
aggregate, it seems at first singular that their entire skeletons 
should be so infrequent. The Mastodon, the Elephant, the 
Musk Ox,’ the Caribou Moose’, and the Reindeer, Horse, Buf- 
falo and Mylodon have been distributed in plistocene and 
recent times as far south as Kentucky, yet except under pecu- 
liar circumstances of sepulture, their remains have disap- 
peared. The conclusion is irresistible that the placement of 
the bones of vertebrates upon the surface of the ground is un- 
favorable to fossilization, that they must be covered in by 
deposits, and while thus held together become hermetically 
sealed against the accidents of surface conditions and the solu- 
tion by carbonated and acid waters. The rhinoceros and ele- 
phant which were disappearing from Sumatra at the time of 
Mr. Wallace’s visit had, after so recent a withdrawal, left few 
traces more than jana, tusks and teeth. Prof. Nordenskiold 
speaking of the polar regions pertinently remarks, “ the Polar 
bear and the reindeer are found there in hundreds, the seal, 
walrus and white whale in thousands, and birds in millions. 
These animals must die a ‘ natural’ death in untold numbers. 
What becomes of their bodies? Of this we have for the pres- 
ent no idea.” 
The isolated death of individuals from packs of wild ani- 
mals or the death of those less social in instinct, does not, un- 
der most circumstances, insure preservation. When some spot 
chosen for its proximity to water, or because of its fertility and 
nourishing vegetation, becomes a rendezvous of groups of ani- 
mals, the herbivores being followed by the beasts of prey, and 
the region thus frequented is so situated as to receive the 
* The Musk Ox, Ovibos cavifrons Leidy, was found in Loess of Iowa at Council 
Bluffs, twelve feet below the surface; also at Ft. Gibson, I. T., St. Louis, New 
Madrid, Mo., Ohio, Big Bone Lick, E. These specimens afforded little else 
than the Sead, separated vertebre and leg bones 
° Bones of the fossil elk or moose have been ial at Big Bone Lick, Kentucky, 
but it was reserved for Prof. W. B. Scott, of Princeton College, N. J., to obtain 
the ‘Magnificent sane mo of Cervaices americanus Harlan now exhibited in the 
