255 



able amount of activity ))ut, witlioul loosiii<^- ils ability to 

 become active again when ))roug'lit back to higher tem- 

 peratures, has led some thinkers (de Caiidolle, 1895; Cho- 

 dat, 1H%; Brown and Kscombe, 1897; etc.) to consider 

 the static aspect of life, w liich is usually overhwked in the 

 classical definitions. An organism which resists extreme 

 cold behaves like a watch which, though well wound, is 

 stopped by some braking meclianism. This watch is in 

 perfect condition as to its constructional features and it 

 will start of its own accord as soon as the brake is re- 

 moved. In a similar manner, the activities of living mat- 

 ter can be stopped entii-ely without destruction of the 

 mechanism which conditions them. This state of affairs 

 is consistent with the hypothesis that the force which con- 

 trols the vital activities requires a special .structure of 

 matter, and that, when that structure is destroyed, the 

 organism is dead, while, when the structure is maintained, 

 the protoplasm is alive, though it might not be active. To 

 use the comparison of de Candolle, an organism in the 

 state of latent life is like an explosive which does not 

 show any evidence of its tremendous potential energy as 

 long as it is not fired. 



SUMMARY 



1. An injurious action of cold, above the freezing point 

 of protoplasm, has been reported in all homoiotherms, 

 in some poikilotherms, in some higher plants and in some 

 undifferentiated living forms. 2. This action, in which 

 the time factor is rather important, has been attributed to 

 a disturbance of physiological functions, to chemical 

 changes, to the accumulation of toxic products, to an al- 

 teration of permeability, to dehydration, to changes in 

 viscosity and in adsorptive properties and to processes 

 of solidification, precipitation and coagulation. .3. A 

 rapid lethal action of cold, above zero, has been reported 

 in a few cases; it has been attributed to syneresis pre- 

 ceded by gelation. 



