Decbmbee 6, 1912] 



SCIENCE 



793 



pollen grains of the South American Podo- 

 carpus in the snow of South Orkney by Dr. 

 Fritsch. 



There are only two phanerogams known 

 from the Antarctic, Descampsia and Oolohan- 

 thus, which are the most southerly flowering 

 plants known. There are no ferns, and. mosses 

 form the major terrestrial plant population, 

 52 species being known, of which 24 are en- 

 demic. The lichens are conspicuous, but few 

 in species. The algse, especially the unicel- 

 lular kinds are abundant. 



All the known facts, according to Dr. 

 Brown, point to a Fuegian origin for the flora. 

 A greater former extension of glaciation, 

 which is well proved, is regarded as inimical 

 to the descent of any part of the present flora 

 from that of Tertiary times. 



Beside the chapters on the botany of the 

 South Orkneys, Gough Island and Ascension 

 Island by Dr. Brown, Cardot contributes a 

 general review of the mosses; Gepp, Holmes, 

 Foslie and Fritsch treat of the fresh-water 

 and marine algse; and Harvey Pirie con- 

 tributes notes on Antarctic bacteriology. The 

 volume concludes with a useful bibliography 

 of Antarctic botanical publications. 



"Wm. H. Dall 



A Text-hooh of Physics. Edited by A. 



WiLMER Duff. Third Edition. P. Blakis- 



ton's Son & Co. 1912. 



The third edition of Dufi's " Physics " is a 

 great improvement typographically over the 

 previous editions, and is consequently so 

 changed that if it were not for the uniform 

 binding of the three editions it would appear 

 at first glance to be an entirely new book. 

 Practically all the cuts have been made over 

 from new drawings, with a noticeable increase 

 in clearness and uniformity of size, or have 

 been replaced by other and better ones. This, 

 with the choice of better type, makes the read- 

 ing much easier. As in the previous editions, 

 the main subdivisions are by different men, 

 but the order has been changed, " Wave Mo- 

 tion " coming after " Mechanics," and " Sound 

 and Light " after " Electricity " ; and there 

 seems to be more unity of treatment in the 



whole and a natural connection between the 

 parts which saves them from appearing as 

 disjointed treatises. The text of the " Me- 

 chanics," by A. W. Duff, is practically un- 

 changed from the previous edition, and the 

 same may be said of " Wave Motion," by E. P. 

 Lewis, and " Sound," by Wm. Hallock. 

 " Conduction of Electricity through Gases 

 and Badioactivity," by E. K. McClung, has a 

 few changes and additions noticing some re- 

 cent developments, but is otherwise un- 

 changed. " Light," by E. P. Lewis, has been 

 reduced in amount and improved by being 

 partly rewritten and rearranged (though it 

 previously possessed considerable merit). The 

 portions on Heat and Electricity and Mag- 

 netism are entirely new. The part on Heat is 

 by C. E. Mendenhall, of the University of 

 Wisconsin, replacing that by K. E. Guthe in 

 the other editions. The arrangement of the 

 subject matter seems to be more logical and 

 more briefly stated, and there is an improve- 

 ment in the choice of illustrations, but in 

 places there is less clearness of statement and 

 treatment than in the previous edition. No- 

 where is the improvement in the drawings 

 more noticeable than in the case of " Elec- 

 tricity and Magnetism," by A. P. Carman, of 

 the University of Illinois, which replaces that 

 by A. W. Goodspeed in the previous editions 

 and comprises also the former section by Pro- 

 fessor Carman on Electromagnetic Induction, 

 thus securing a desirable unity of treatment 

 in this subject. Taken as a whole the parts of 

 the book are remarkably well welded together, 

 and, having as authors specialists in the dif- 

 ferent departments, it should rank among the 

 best college texts of the day. 



Louis A. Parsons 



Maschinen und Apparate der Starhstromtech- 

 nik (Machines and Apparatus for Heavy 

 Currents). By Gustave M. Meyer. Pub- 

 lished by B. G. Teubner, of Leipzig and 

 Berlin. 1912. 



So rapid has been the development of 

 machines and apparatus used in connection 

 with the many applications of electricity to 

 power purposes that it is well-nigh impossible 



