548 



SCIENCE. 



[N. S. Vol. I. No. 20. 



•other country in intellectual interests. But 

 AxQcrica has a special reason for pajdng her 

 respects to the genius of Helmholtz, since 

 Hehnholtz in his seventy-second year paid 

 his tribute of respect to the genius of Amer- 

 ica. One year before his death he crossed 

 the ocean to study and to enjoj^ the scien- 

 i;ific institutions of this country from the 

 Atlantic to the Eocky Mountains, certainly 

 the most famous European who has visited 

 America for many years, and nobody who 

 saw his noble personality in New York or 

 Boston or Baltimore, in Philadelphia or 

 Washington or Chicago, will ever forget 

 him. 



The American members of the Interna- 

 tional Committee are Dr. Wolcott Gibbs, 

 President of the National Academy of Sci- 

 ences ; Dr. Herman Knapp, Professor of Co- 

 lumbia College; and Dr. Hugo Miinsterberg, 

 Professor of Harvard University. 



Conti'ibutions may be sent before May 

 25th to the undersigned Secretary and 

 Treasurer of the American Committee. 

 The lists of contributors will be published 

 weekly in Science. 



Hugo Munsteebeeg. 



38 QuiNCY SteeeT; Cambridge, Mass. 



SCIENTIFIC LITERATURE. 

 Manual of Geology. By James D. Dana. 



Fourth Edition. American Book Co. 



1895. 



The announcement, a few months ago, of 

 a new edition of Dana's Manual filled ge- 

 ologists with liveliest expectations. It is 

 needless to say that these expectations are 

 more than realized. The Manual is so well 

 known that a full account is whoUj' un- 

 necessaiy — geologists need no urging to 

 buy it. They simply must have it ; they 

 cannot do without it. I %vi'ite this, there- 

 fore, not to call attention to the book ; but 

 partly because I am glad to have this op- 

 portunity to express my unstinted admira- 

 tion for the author and for the book ; and 



partly because I wish to draw attention to 

 the author's position on some important 

 questions which have come into prominence 

 since the last edition. 



1. Eveiy geologist will be gratified to 

 see that the author now comes out frankly 

 for evolution ; not, indeed, evolution in a 

 materialistic sense, but in a reverent, theis- 

 tic sense. In a certain Agassizian sense 

 he has always been an evolutionist, but he 

 has been often quoted by the o2^ponents of 

 evolution as now understood (i. e., ' origin 

 of organic forms hj descent with modifica- 

 tions ') as sustaining their position. In 

 this edition his utterances are not to be any 

 longer mistaken ; although he is, perhaps, 

 more nearly Lamarckian than Darwinian, 

 or, at least, than ISTeo-Darwinian. Surely 

 such plasticity and open receptiveness of 

 mind retained even to the very last is a 

 noble evidence of the true scientific spirit. 



2. In this edition he separates the Palae- 

 ozoic into two primary divisions with Eo- 

 Palceozoic, including the Cambrian and Lower 

 Silurian, and the Neo-Palceozoic, includtag 

 the Upper Silurian, Devonian and Carbonic. 

 Thus he makes the greatest break occur be- 

 tween the Lower and Upper Silurian. If 

 this be so, would it not be better to use 

 Lap worth's term ' Ordovician ' for Lower 

 Silurian, retaining the term Silurian for the 

 Upper Silurian alone ? Probablj^ this would 

 violate the priority-rule of nomenclature; 

 but, perhaps in this, as in many other cases, 

 rules too strictlj^ interpreted stand in the 

 way of a rational classification. 



3. He accepts the probability of a Per- 

 mian glaciation, especially in the Southern 

 Hemisphere ; and of an elevation and en- 

 largement of an Antarctic continent and 

 its connection with the southern points of 

 South America, South Africa and Australia 

 as a cause of such glaciation. These great 

 changes of phj'sical geography and climate, 

 and consequent wide migrations of faunas 

 and floras, would go far to account for the 



