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SCIENCE 



[N. S. Vol. XXXIII. No. 842 



tendency in all branches of natural history; 

 and the writer deplores it. Is it not just as 

 well to call these chief groups orders with as 

 little disturbance as possible to existing plans 

 of classification? For, after all, it seems to 

 be merely a question of names. However, 

 classification of organisms is an art that 

 passes understanding, and no one knows where 

 it will end; possibly when all the species have 

 been raised to genera and all the genera to 

 families, and families to orders, etc. 



Perhaps the most widely useful part of the 

 work is reserved for the conclusion of this 

 review — the introductory chapter. In this the 

 author brings together in a readable way the 

 underlying principles of paleontology, with 

 especial reference to mammals, but also widely 

 applicable, not only to all branches of paleon- 

 tology, but to all natural history as well. The 

 philosophy of structure, correlation, range, 

 environment, the laws of evolution as apply- 

 ing to mammals in general and in detail, are 

 among the subjects treated. Not all is dis- 

 cussed that might have been; not all the con- 

 clusions are beyond controversy, but, withal, 

 it is the best summary of the guiding prin- 

 ciples of paleontological research the writer 

 has seen. 



The writer can not recommend the work as 

 one suitable to slip into one's grip for literary 

 recreation on a vacational outing — it is a 

 little heavy and forbidding in places. As a 

 work of reference for the geologist and nat- 

 uralist it is indispensable; and it will be a 

 working tool for the student of estinct mam- 

 mals. Perhaps, with the publication of this 

 work there will no longer be an excuse for the 

 further display of the dense ignorance con- 

 cerning extinct forms that characterizes the 

 most of our text-books in zoology — at least let 

 us hope so ! 



In conclusion it may be said that this inven- 

 tory of extinct mammals has been well done; 

 the way is again cleared for a further rapid 

 expansion in our knowledge of this class of 

 vertebrates. And the author is to be com- 

 mended and congratulated on the opportuni- 

 ties he has aided in opening up. 



S. W. WiLLISTON 



Catalogue of the Nearciic Eemiptera-Hete- 

 roptera. By Nathan Banks. Philadelphia, 

 Pa., American Entomological Society. 1910. 

 This catalogue covers the entire group of 

 Heteroptera for the Arctic region, and in this 

 respect is of much greater service to the 

 American student than the general catalogue 

 of Kirkaldy which includes only a few of the 

 families represented in this region. The work 

 is rather a presentation of the existing 

 knowledge than an attempt to rearrange the 

 grouping or to introduce radical changes in 

 the generally accepted nomenclature. The 

 list covers 1,268 species and is particularly 

 serviceable in certain families which have 

 not been treated in recent years. Such a cat- 

 alogue has been much needed, as the only 

 work of a similar character, the list by Dr. 

 Uhler, published over twenty years ago, is 

 long since out of date. The paper shows some 

 defects in proof reading, as for instance, the 

 misspelling of Macrovelia and Zicrona, but on 

 the whole it seems to be quite free from seri- 

 ous error. We can certainly share with the 

 author the hope " that this catalogue will en- 

 courage entomologists to devote more time to 

 this order, so that our forms will be better 



known to us." 



Herbert Osboen 



The Relation hetween Chemical Constitution 

 and some Physical Properties. By Samuel 

 Smiles, D.Sc, New York, Longmans, Green 

 and Co. 1910. 



The study of the relations between the 

 chemical constitution and the physical prop- 

 erties of substances has interested chemists 

 and physicists for a greater period of time 

 than has the study of any other branch of 

 chemistry which possesses more or less gen- 

 eral interest at present. Por this reason, the 

 volume under review should exert a wider 

 appeal than any which have appeared in the 

 series of " Text-books of Physical Chemistry " 

 edited by Sir William Eamsay, of which it 

 forms a part. As part of a physical chemistry 

 series it will appeal to physical and inorganic 

 chemists, and it will also appeal to organic 

 chemists, since as stated by Professor Smiles 



