58 WHAT 18 LIFE 



the Russian physiologist Kuljabko's experiments on 

 the hearts of dead children, carefully prepared salt 

 solutions caused the dead hearts to beat again. This 

 is the more significant since — to quote Dr. Walter 

 H. Gaskell — "the heart's motto, as Ranvier and 

 Kronecker and Meltzer put it, is, 'All or none'; 

 either it will not contract at all, or it will contract 

 to the fullest extent possible at the time." 



Temperature is an important factor in the meta- 

 bolic and other processes of the organism as it is in 

 inorganic reactions, and variations in temperature 

 directly modify life-processes. This has long been 

 known through the research of J. Sachs, ^ and of 

 others. Askenay^" and A. Kanitz^^ treated of it. Uh- 

 lenhuth has shown that temperature influences the 

 time of the metamorphosis in salamanders. Jacques 

 Loeb and others have shown that changes in the 

 temperature of the air in which fruit-flies (Droso- 

 'phila) are kept, directly determine a shorter or 

 longer term of life of the flies. By lowering the tem- 

 perature of fruit-flies twenty degrees Loeb prolonged 

 the duration of their life by nine hundred per cent.^^ 



« "tJber den Einfluss der Lufttemperatur und des Tageslicht auf die stiind- 

 lichen und taglichen Xnderungen des Langenwachstums." Arheiten des Wiirz- 

 berger Institut, 1872, 1. 



1" "tJber einige Beziehungen zwischen Wachstum und Temperatur." Be- 

 richte der Botanischen Gesellschaft, VIII (1890). 



'^ Temperatur und Lebensvorg&nge. 



" Scientific Monthly, December, 1919. 



