154 Cincinnati Society of Natural History. 



taken from the p ts of the older mounds are very fragile — time has 

 disintegrated them. 



A few years ago the underjaw of an elephant (extinct variety) 

 was unearthed while quarrymen were excavating a sewer on Central 

 Avenue (this city). The bone was at least 40 feet above the late 

 inundation, and deeply buried in gravel, and in a too good state 

 of preservation to be ten thousand years old. In a cave or peat- 

 bog, where chemicals of a protective nature are present, a bone may 

 be preserved a million of years, but not in a gravel bank. In 

 the course of time a bone loses its cohesive properties, and crum- 

 bles like slacked lime. Possibly the elephantine maxilla recently 

 exhumed, and the fossil skull, have been buried in their pebbly 

 beds for 1500 years ; yet their firmness could not be maintained for 

 thousands of years. It will be excusable in me if I do not venture 

 into a broader speculation ; but the subject is open to free discus- 

 sion. That the Borreby skulls of Denmark, and the Enghis and 

 Neanderthal crania, are older than the one under observation, I 

 have not the slightest doubt. In fact, I look upon this as conii)ara- 

 tively modern. There is a question about the antiquity o{ the 

 Calaveras skull — an earthquake may have determined the overlay 

 or superposition. Herculaneum was buried two thousand years 

 ago; and the skeletons of the overwhelmed inhabitants are well 

 preserved ; and it is not improbable that they may continue to 

 resist disintegration for ten thousand years. I mention the circum- 

 stances to illustrate how uncertain it is to speculate upon the age 

 of fossils. 



