September 30, 1910] 



SCIENCE 



43^ 



Carnegie Institution of Washington has for 

 five years furnished the funds necessary for 

 the preparation of the manuscript and for the 

 publishing of the tables." He also acknowl- 

 edges gratefully sufficient temporary relief 

 from academic work in the University of Cali- 

 fornia to afford opportunity to devote more of 

 his time to the arduous task of most careful 

 proof-reading, for errors in such work are not 

 suggested by the context, and the author wisely 

 observes that " the value of a factor table de- 

 pends chiefly on its freedom from errors." 



The introduction includes a valuable list of 

 corrections to earlier extensive tables and di- 

 rects attention to " the manuscripts of Kulik 

 which were placed in charge of the Vienna 

 Eoyal Academy in 1867. These tables were 

 said to give the smallest factor of all numbers 

 not divisible by 2, 3 or 5 up to the limit of 

 one hundred million!" The author of the 

 present table saw only the first one of the six 

 volumes of Kulik's manuscript, and furnishes 

 a rather extensive list of errata in the tenth 

 million. He also includes, in the introduc- 

 tion, a short historical account of the earlier 

 factor tables as well as some remarks on the 

 methods of constructing such tables. In every 

 way the present table appears to deserve a very 

 high place among the American mathematical 

 publications of permanent value, and both the 

 author and the Carnegie Institution have ren- 

 dered a great service not only to the mathe- 

 matical public but also to many who make 

 only occasional use of mathematics. 



G. A. JMlLLER 



Univebsity of Illinois 



SHACKLETOyS C0yTRIBVTI02f TO 

 BIOGEOGRAPHY 

 It has long been surmised that certain south 

 polar lands may have one time connected sev- 

 eral of the main biogeographic regions of the 

 earth. Wilkes Land, South Victoria Land 

 and Graham Land, with other near-by lands 

 more recently named, have been conceived as 

 forming a continent, which in times past may 

 have stretched its shores to connections with 

 the other continents of the southern hemi- 

 sphere. Shackleton's recent work in Ant- 

 arctica has now placed the existence of that 



continent in the realm of fact. Surmise has 

 given way to certainty. We are now in posi- 

 tion to deduce certain conclusions from its 

 existence and the known conditions pertaining 

 to it. In the hope of stimulating discussion 

 of the general subject by those more versed in 

 paleogeographic data than myself, I venture to 

 state the following aspects of Shackleton's dis- 

 coveries as they appear to the student of geo- 

 graphical distribution. 



During past geologic ages, with the excep- 

 tion of certain relatively brief intervals of 

 change, Antarctica has, in common with the 

 rest of the globe, enjoyed comparative freedom 

 from ice, excepting only the presence of alpine 

 glaciers, and been blessed with an equable tem- 

 perature. In those days the wide-stretching 

 south polar land comprised an immense conti- 

 nent whose thousands of miles of extent were 

 for the most part quickened by a mild climate 

 and populated with an abundant life. Here 

 during Paleozoic, Mesozoie and Tertiary time 

 was a wonderfully rich territory, its resources 

 now practically lost to us under an all -per- 

 vading ice-sheet. Shackleton's party found 

 evidence of extensive coal deposits, including 

 remains of forested areas, indicating an abun- 

 dant flora and fauna. Let us see what light 

 the former existence of such favorable biotic 

 conditions throws on the present distribution 

 of life with reference to Australia, South 

 America and Africa. 



Australia and Xew Zealand, occupying ap- 

 proximately longitude 110° to 180° east from 

 Greenwich, are almost opposite the southern 

 extremity of South America, which is about 

 longitude 70° west from Greenwich. The 

 southern limits of Australia and New Zealand 

 are in latitude 40° to 50° south, those of South 

 America in latitude 55° south. Thus there 

 intervenes between these present land divisions 

 an actual distance of only 75° to 85° by way 

 of the south pole. The straight-away line 

 between the centers of the two masses passes 

 well to one side of the pole, and the inter- 

 vening distance between their southern limits, 

 but practically across the heart of the south 

 polar region, may be roughly stated as 4,500 

 geographic miles. The southern ocean sound- 

 ings so far made reveal shallow depths, or epi- 



