viii THE ANTIQUITY OF MAN IN NORTH AMERICA 447 



of clay and gravel. The most remarkable discovery, however, 

 is that known as the Calaveras skull. In the year 1866 some 

 miners found in the cement, in close proximity to a petrified 

 oak, a curious rounded mass of earthy and stony material 

 containing bones, which they put on one side, thinking it was 

 a curiosity of some kind. Professor Wyman, to whom it was 

 given, had great difficulty in removing the cemented gravel 

 and discovering that it was really a human skull nearly entire. 

 Its base was embedded in a conglomerate mass of ferruginous 

 earth, water-worn volcanic pebbles, calcareous tufa, and frag- 

 ments of bones, and several bones of the human foot and 

 other parts of the skeleton were found wedged into the 

 internal cavity of the skull. Chemical examination showed 

 the bones to be in a fossilised condition, the organic matter 

 and phosphate of lime being replaced by carbonate. It was 

 found beneath four beds of lava, and in the fourth bed of 

 gravel from the surface ; and Professor Whitney, who after- 

 wards secured the specimen for the State Geological Museum, 

 has no doubt whatever of its having been found as described. 



In Professor Whitney's elaborate Eeport on the Auriferous 

 Gravels of the Sierra Nevada, from which most of the pre- 

 ceding sketch is taken, he arrives at the conclusion that 

 the whole evidence distinctly proves "that man existed in 

 California previous to the cessation of volcanic activity in the 

 Sierra Nevada, to the epoch of greatest extension of the 

 glaciers in that region, and to the erosion of the present river- 

 canons and valleys, at a time when the animal and vegetable 

 creations differed entirely from what they are now, and 

 when the topographical features of the State were extremely 

 unlike those exhibited by the present surface." He elsewhere 

 states that the animal and vegetable remains of these deposits 

 prove them to be of "at least as ancient a date as the 

 European Pliocene." 



Professor Whitney enumerates two other cases in which 

 human bones have been discovered in the auriferous gravel, 

 and in one of them the bones were found by an educated 

 observer, Dr. Boyce, M.D., under a bed of basaltic lava eight 

 feet thick ; but these are of but little importance when com- 

 pared with the preceding cases, as to which we have such full 

 and precise details. The reason why these remarkable dis- 



