CORRESPONDENCE AND INFORMATION 



385 



iter and pitted by the wind. Such 

 -concretions are common in many sand- 

 tones. They assume many shapes, and 

 we can no more say why this one is 

 like a cigar while another is spherical 

 than we can say why one crystal has 

 six sides and another five. In desert 

 •countries the rocks break up under 

 the inrluerce of heat and cold with a 

 ■tendency toward prismatic forms. This 

 piece looks as if it had been 1 oiled on 

 the shore of the old expanded Salton 

 Sea, but of course I cannot be sure 

 vvithout knowing the exact elevation. 

 It may simply have been rolled by run- 

 ning water. Since the rolling process 

 was completed it has lain in such a po- 

 sition that the winds have blown bits of 

 •sand against it and have worn the lit- 

 tle pits with which it is covered, es- 

 pecially at the butt end. I am sorry 

 that I cannot tell just why it is cigar- 

 shaped, but that is beyond the knowl- 

 edge of any mortal man. 



The other stone is to me much more 

 interesting because it is a sample of 

 the work of Neolithic man. Take it in 

 vonr hand with the two little hollows 



up and facing away from you. Put 

 your thumb in the larger hollow and 

 your forefinger in the smaller, and 

 grasp the stone as if to throw it. Such 

 throwing stones were in common use 

 among early men. Some ancient hunt- 

 er picked out the roundest stone he 

 could find in the stream-bed, and then 

 laboriously polished it. The success of 

 his work is seen in the smooth top and 

 uottom. He chipped out holes for his 

 fingers, and used the stone to throw at 

 animals. After he died and the desert 

 became drier than formerly, the stone 

 lay where it was exposed to the cutting 

 action of sand drifted by the wind. 

 The top and bottom escaped without 

 change, but on the sides, where the 

 moving sand grains struck with force, 

 innumerable little pits have been carved 

 and the finger holes have been smooth- 

 ed. The material looks to me like im- 

 pure chalcedony or hornstone, but I 

 cannot be sure without chipping into it. 

 — Ellsworth Huntington, Y r ale Univer- 

 sity, New Haven, Connecticut. 



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A VIEW OF THE THIRD SPECIMEN, AN ENCRUSTING P.RYOZOON, UNDER A MICROSCOPE 



