Geology and Natural History. . 483 



analyses of fresh and altered rocks being given, and is a useful 

 addition to the general literature of scientific petrography as well 

 as a fund of information for local technical purposes. It is well 

 printed and illustrated by a large number of excellent half tone 

 cuts and is a production creditable alike to the author and to the 

 state survey. . l. v. p. 



5. I?Age Des Formations Sediment aires de Patagonie; by 

 Florentino Ameghino. " Annals Soc. Cientif. Argentina," L 

 and LIV, pp. 3-231, Buenos Aires, 1903. — It is not my intention 

 to review this rather lengthy paper, the exact nature of the con- 

 tents of which is scarcely intimated by the title. Nor does Dr. 

 Ameghino's declaration on page 5 that " C'est une discussion 

 exclusivement scientifique que ja vais tacher d'examiner en con- 

 science et sans aucun prejuge," seem to have been kept con- 

 stantly in mind throughout the succeeding 225 pages. The 

 entire paper is devoted almost exclusively to a critical review of 

 the literature of various authors upon the geology and paleontology 

 of Patagonia, and the amount of space allotted to the three or 

 four brief preliminary papers published by myself (this Journal, 

 iv, 246-248; 327-354; ix, 85-108) is such that I ought certainly 

 to feel nattered by the attention bestowed upon my work in 

 Patagonia by Dr. Ameghino, the learned director of the National 

 Museum at Buenos Aires. However, for the benefit of those who 

 may not have access to Dr. Ameghino's paper, it is only proper 

 for me to state in this connection that Dr. Ameghino's estimation 

 of the value of my work in Patagonia is in inverse proportion to 

 the space he has devoted to its criticism. 



As to those matters relating purely to the geology and paleon- 

 tology of Patagonia, wherein we differ, I shall have nothing to 

 say at present. Having already stated my opinions and 

 given in some detail my reasons therefor in my preliminary 

 papers, I am content to await the publication of my final report 

 on the geology of that region for a further elucidation of my 

 views. In the meantime I must refer those interested in these 

 questions to such of my publications as have already appeared, 

 where they will find all important localities mentioned by me 

 designated and described with such detail that they may be 

 revisited and re-examined. I am so far from considering myself 

 as infallible that I have always taken the precaution to preserve 

 and publish detailed descriptions of all important localities in 

 such manner that they may be easily revisited and identified by 

 subsequent investigators. I shall always respect the opinion of 

 any really competent observer, who revisits and re-examines any 

 of the localities visited by me in Patagonia, regardless of whether 

 his interpretation of the facts there displayed do or do not agree 

 with those of myself. I do, however, believe that geology as a 

 science is somewhat different from astronomy, and that it can 

 only properly be studied at close range and not from a distance. 

 Even so capable a man as Dr. Ameghino should, I believe, find 



Am. Jour. Scl — Fourth Series, Vol. XV, No. 90.— June, 1903. 

 33 



