280 



the (Inui.'inc by freezing' I'csulls not only from llic water 

 witlulrawal itsclt" but also t'loiii a pri'cijjilatioii ol" tlic col- 

 loids of the protoplasm. Sudi a i)recipitalioii would be 

 caused by ])otli an increased concentration of the colloids 

 subsequent to ficcziiii;- and by a mechanical compression 

 between the k'v masses. The connnon action of these two 

 factors would be to brin^' the colloidal i)ai-ticles of pro- 

 toplasm in too close a proximity so tliat coagulation 

 would result. 



Having admitted a mechanical action of ice on the 

 precipitation of colloids, Maximov considers as answered 

 the objection of Pfetfer and others to the dehydration 

 theory, namely, that some plants withstand desiccation 

 while they are killed by freezing. The factor pressure, 

 present in freezing, is absent in desiccation. 



The fact pointed out by Maximov himself (1912) that 

 immersion in a concentrated solution protects a tissue 

 against the action of cold except if the temperature of 

 the solution is below the cryohydrate point, is brought 

 to supi)ort the theory; above the cryohydrate point the 

 etTect of pressure by ice is lessened by the fact that a 

 part of the solution is liquid and gives way under 

 pressure. 



Maximov departs in some minor ])oints from ]\luller- 

 Thurgau's views; for example, he denies that the rapid 

 water withdrawal after subcooling is the cause of death 

 since he observed that the death temperature was about 

 the same when freezing w^as preceded by a considerable 

 subcooling and when there was no subcooling. 



He criticizes Fischer's theory that death by cold con- 

 sists in the loss by the protoplasmic colloids of the ca- 

 pacity for adsori)tion, saying that only a small portion 

 of water is adsorbed in protoplasm, the rest is "free" 

 water, held in the cell by osmotic forces, not by adsorp- 

 tion. The release of water after death is explainable, 

 according to Maximov, who here quotes Niigeli (ISGl), 



