5i8 



ON INCREASE IN SIZE 



[PT. Ill 



closely associated with hydroxyl ion catalysis. Glaser suggested that 

 the value of 8000 which he found for a phase of Paramoecium loco- 

 motion was associated with hydrolysis. Crozier & Stier found that 

 the [x for various processes in the grasshopper was quite different after 

 decapitation to what it had been before, changing from 7900 to 

 16,500, and showing that, after central nervous system control had 

 been removed, an oxidation was the slowest reaction. "The velocities 

 of vital processes", said Crozier, "are determined by the velocities of 

 dynamically linked systems of chemical transformation differentially 

 affected by external conditions." Table 73 gives a resume of the 

 commonest [x values and their significances. 



Table 73. 



Significance 



4,7001 

 8,000 I 

 9,000 f 



1 0.000 j 

 11,300 



1 2.000 1 



I2,500[ 



16,000) 

 i6,6ooJ 

 18,000 

 20,000 

 24,000 

 27,000 



Physico-chemical 

 Hydrolysis or diffusion 



Biological 



( Protoplasmic streaming 

 < Rate of nerve conduction 

 (Rate of moving algae 



Hydroxyl ion catalysis of oxidations Oxygen consumption 

 Breaking of i sulphur linkage Nervous factor 



Catalysis by iron dehydrogenation 

 Activation of iodine 

 Hydrogen ion catalysis 

 Certain hydrolyses 



Oxidation, oxygen consumption 



Growth 



In 1926 Crozier marshalled all the values that had been obtained 

 for p, in biological processes into a frequency polygon, from which 

 it appeared that the commonest types of fx were roughly 8000, 

 11,000 and 16,000; above that the peaks or modes were not so 

 striking, for the observations were fewer. He also marshalled all the 

 values that had been obtained for breaks in temperature charac- 

 teristics at definite temperatures into another frequency polygon, 

 from which it appeared that 15° was by far the most important of 

 these, but that 8°, 20° and 30° were also associated to some extent 

 with abrupt breaks in the values of /x. Less common were breaks 

 at 4*5°, 25° and 27°. That both these polygons are definitely multi- 

 modal is a fact which makes the whole position more convincing 

 than it might have been; for, if chance had been operating alone, 

 there would have probably been but one peak. 



