214 THE AMERICAN NATURALIST. [VoL. XXXV. 
intermixed with larger masses of the rock. This talus is 
constantly forming, and the colored patches along the face 
of the cliff mark the places from which masses of felsite have 
recently fallen, which are shattered as they strike the rocks 
below, and the larger pieces rolling down the slope are chipped 
and broken into innumerable forms. The recently fractured 
pieces are easily distinguished from those which have been 
long exposed to the action of the atmosphere. The fresh frac- 
ture presents a green surface sprinkled with small dots and 
squares of gray feldspar crystals. Upon long exposure the 
surface becomes a uni- 
form dirty gray. Upon 
this slope one can gather 
bushels of chips, flakes, 
and pseudo-implements 
wholly the work of 
nature, which, if placed 
unlabeled on the shelves 
of a museum, would be 
accepted without ques- 
tion as the work of man. 
For comparison a series 
of these natural forms is 
shown with an equal 
number from Indian 
J workshops at a distance 
Fic. 2. —* map of Mt. Kineo and ad showing from the mountain. In 
ocation of Indian workshop 
selecting the natural 
forms care was taken to include only those lying on the sur- 
face near the top of the talus and having the green color 
indicating freshly fractured stone. Only a few of the many 
examples collected are shown. The natural forms are illus- 
trated on Pl. I, z to 7. The artificial forms from the workshops 
are shown upon the same plate, a to f. Typical artificial chips 
showing the “ bulb of percussion” are seen in e and f, while 4 
and / show natural chips having corresponding bulbs. These 
* bulbs of percussion" are generally accepted as conclusive 
evidence of the artificial origin of such flakes. 
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