270 



vestigators who tlion^lil tli;i1 lliawiiii;' in wator should be 

 slowiM- tliaii tliawiii^' in air, at the same UMnporatiire). 



Molisc'h ( lSi)7), who reviowed the ])i-ol)k'iii of death by 

 rapid thawing-, himself made a large number of experi- 

 ments on this ])oint. He use<l mostly leaves of various 

 higher phints, in i)artienhir, of Af/rrdhnu in wiiich deatli 

 can be diagnosed by the o(h)r of couniarin released from 

 the cells. He also performed some experiments with 

 algae of the class Florideae, which change their color at 

 death. Ka])id tliawing was carried out in water at 30° ; 

 for slow thawing the material remained 5 hours at -1°, 

 5 hours at and then it was brought to 2 \ The leaves 

 were cut longitudinally in two, one half being thawed 

 ra])idly, the other slowly. The author concludes that the 

 rapidity of thawing had no effect on survival except in 

 one case, namely with the plant Agave. 



According to Sorauer (Handbuch der Pfianzenkrank- 

 heiten, 1909) frozen leaves of Cineraria presented dead 

 spots only at places where they had been thawed too 

 rapidly between the warm fingers. 



Hedlund (1912, quoted by Akerman, 1919), also found 

 that plants frozen at moderately low temperatures can 

 be saved by slow thawing. 



Winkler (1913) on the contrary, came to the conclu- 

 sion that survival is not controllc^d l)y the rapidity of 

 the thawing. 



Chandler (1913), experimenting on fruit and vegeta- 

 bles, found in exceptional cases some evidence of a more 

 injurious action of rapid thawdng; in general, however, 

 the rapidity of thawing made no ditference on the re- 

 sults. 



Akermann reviewed this subject (1913) and himself 

 made a systematic series of observations on the effect 

 of rapid and slow^ thawing on various plants (red cab- 

 bage leaves. Viburnum, Aucuha, potato, Tradescantia). 

 He concludes that slow^ thawing might play a role in 

 saving from deatli some species of frozen ])lants ])nt 



