980 



SCIENCE 



[N. S. Vol. XXXVII. No. 965 



must all who use their material. It is impos- 

 sible to go back of tbeir record. As they 

 (the vertebrate paleontologists), although fully- 

 aware of the fragmentary condition of the 

 material they dealt with, gave not only gen- 

 eric but specific names and made certain de- 

 ductions from their use, I do not quite under- 

 stand why I was so sadly misled in using the 

 names as I did, unless, as I said in my paper, 

 vertebrate paleontology is of no use to the 

 stratigraphic geologist. I wish to state here 

 that I thoroughly believe in the value of the 

 evidence of vertebrate paleontology. 



While upon this subject, I wish to refer to 

 another point, not, however, mentioned by 

 Dr. Matthew. By some I have been criticized 

 for not including in the lists of vertebrate 

 fossils in my paper all that have been in any 

 way referred to the Judith River formation, 

 from all localities in Montana and in Canada, 

 but it was my idea to limit the list to those 

 found in the typical region of the Judith 

 Eiver formation, and on page 753 of my 

 article on the " Stratigraphic Position and 

 Age of the Judith Eiver Formation" it is 

 distinctly stated that Hatcher's list of Judith 

 River vertebrates is used after the elimination 

 of " all the species which are duplicated under 

 other names " and also of all which come from 

 beds not certainly of Judith age or that occur 

 outside the typical area (the Judith Basin of 

 Montana). A. 0. Peale 



ICE CAVES 



The contribution to The Popular Science 

 Monthly for March on " The Sweden Valley 

 Ice Mine," by Marlin O. Andrews, calls for 

 some comment and criticism. In the first 

 place it is calculated to convey the impression 

 that such phenomena as he describes are ex- 

 ceedingly rare, whereas they are fairly com- 

 mon in middle latitudes — especially in lime- 

 stone districts. In the second place the expla- 

 nation given of such phenomena is faulty. 



The writer of the above mentioned article 

 appears to have come to his subject rather 

 poorly equipped as regards geological knowl- 

 edge, and though by his own statements sup- 

 plied by the Federal Survey with information 



concerning the literature of the subject, to 

 have availed himself very little of it. To be- 

 gin with, his introduction detailing tradition 

 as to presence in the region of silver mines 

 known only to the Indians, in regard to the re- 

 liability of which he appears to have little 

 doubt, does not serve to enhance our confidence 

 in his ability to describe or explain geological 

 phenomena. 



Such traditions of " lost silver mines " pre- 

 vail in nearly every community, but we hardly 

 expect to find a man of science giving cred- 

 ence to them; especially if it is in a region 

 where such mines are a geological impossibil- 

 ity. Potter County, Pa., is in such a region. 

 It may be true that the county has never been 

 covered by a detailed geological survey (a por- 

 tion of it however has been covered by the 

 Federal Survey and an account given of it in 

 the Gaines Folio), but enough is known geo- 

 logically of that portion of Pennsylvania to 

 enable us to postulate the presence there of 

 unaltered and little deformed sandstones and 

 shales of Devonian and Carboniferous age, 

 and to assert the entire absence from them of 

 deposits in appreciable amounts of either lead 

 or silver ores. Will the time never come when 

 the diffusion of elemental geological knowl- 

 edge is such as to render impossible the float- 

 ing of such absurd " lost-silver-mine-known- 

 only-to-the-Indian traditions " ? Where did 

 these Indians acquire their expert mineralog- 

 ical and metallurgical knowledge that would 

 enable them to detect silver in an ore or ex- 

 tract it therefrom? We know that when dis- 

 covered by white men the American Indian 

 was living in the " Stone Age " and utterly 

 unacquainted with the extraction of metals 

 from their ores. 



When it comes to the account of the ice 

 mine itself, the description in the article must 

 be considered very inadequate from a geolog- 

 ical point of view. Was the shaft sunk on un- 

 disturbed strata or on talus accumulation ? If 

 on the latter, we appear to have here a case of 

 " talus ice accumulation," of which there are 

 many instances. There is at least one other 

 of these in Pennsylvania, if I remember cor- 



