SCIENCE 



Friday, August 27, 1920 



CONTENTS 

 The Temperature Interval in the Geograph- 

 ical Distribution of Marine Algce: Pko- 

 PESSOB "William Albert Setchbll 187 



A Third Capture on the Florida Coast of the 

 Wliale Shark, Bhitieodon typus: Dr. E. W. 



GUDGEE 191 



Scientific Events: — 

 The Spawning Grounds of the Eel; Agri- 

 cultural Worh at the University of Nanking; 

 All-America Conference on Venereal Dis- 

 eases; Dye Division of the American Chem- 

 ical Society; The Federated American Engi- 

 neering Societies . .-, 192 



Scientific Notes and News -. 195 



University and Educational News 197 



Discussion and Correspondence: — 

 Methods used in the Study of Soil Alkali: 

 Dr. F. S. Harris. The Role of Psychological 

 Factors in Digestion: Dr. J. E. Kantoe. A 

 Sidewalk Mirage : Dr. F. W. McNaie 198 



Scientific Books : — 

 Dean on Helmets and Body Armor in Mod- 

 ern Warfare: Dwight Franklin 201 



Special Articles: — 

 Decomposition of Hydrogen Peroxide hy Or- 

 ganic Compounds and its Bearing on the 

 Catalase Reaction: Drs. Sergius Morgultjs 

 AND Victor E. Levine. Device showing ef- 

 fect on the Potential Difference between the 

 Terminals of an Electric Cell when the Cir- 

 cuit is closed: Dr. Norton A. Kent 202 



The Americam Meteorological Society: De. 

 Charles F. Brooks 295 



The American Chemical Society: Dr. Chaeles 

 S. Parsons 206 



MSB. intended for publication and books, etc., intended for 

 review should be sent to The Editor of Scienoe, Garriaon-on- 

 HudBon, N. Y. 



THE TEMPERATURE INTERVAL IN 

 THE GEOGRAPHICAL DISTRIBU- 

 TION OF MARINE ALG-ffii 



The idea of geograpliical distribution came 

 as a new and inspiring, although rather in- 

 definite, concept to the German fathers of 

 botany in the latter portion of the fifteenth 

 and earlier portion of the sixteenth centuries. 

 The attempt to explain geographical distribu- 

 tion according to the influence of environ- 

 mental factors began, practically, with Alex- 

 ander von Humboldt in 1805. Since his time, 

 temperature has generally been regarded as 

 the chief limiting factor in climatic distribu- 

 tion. In 1893, I called attention to the rela- 

 tionship existing between the position of the 

 isotheres (mean maxima for the hottest 

 month) of 10°. 15°, 20°, and 25° 0. of the 

 surface waters of the oceans and the limits 

 of distribution of certain groups of kelps 

 (Laminariacese). In 1894, and again in 1898, 

 C. Hart Merriam proposed dividing the United 

 States into certain " life-zones " or " crop- 

 zones " according to the " summation-indices " 

 of the temperature of the frostless season and 

 showed the close relation of the boimdary 

 lines of these " zones," or belts as they may 

 be more distinctly designated, to the isotheres 

 (isotherms of mean maxima for the six hot- 

 test weeks of the season) of 18°, 22°, and 

 26° C. In 1913, Livingston and Livingston 

 proposed a series of " efficiency indices " for 

 use in plant distribution and climatology, 

 presumably resting upon more of a physiolog- 

 ical basis than the summations of tempera- 

 ture or statistical relations to various iso- 

 therms. The efficiency basis of their system 

 is founded upon the application of the van't 

 Hofl-Arrhenius principle as to the velocity of 

 vital activities at different temperatures. In 



1 Delivered before the Princeton Biological 

 Seminary on April 6, 1920. 



