THE PROCESSES OF DEPRESSION 355 



ture of 14-40° C, and on the other, in one merely a few degrees 

 above zero. He found that the nerves of the cooled frogs re- 

 quired on an average twice or three times as long for their irri- 

 tability to sink to the same degree as those of the heated frog, 

 although during the experiment the same temperature was present 

 in both. It was also shown that the asphyxiation period was pro- 

 longed up to a certain limit, depending upon the length of time the 

 animals were kept at a low temperature. It would seem to me 

 that these facts admit of no other explanation than that in a low 

 temperature a greater amount of oxygen is stored in the nerve 

 than in high temperatures. From the standpoint that from the 

 moment of withdrawal of oxygen from without, disintegration 

 likewise takes place exclusively anoxydatively, these facts would 

 be completely incomprehensible. When, however, the assump- 

 tion is made, and this would appear to me as inevitable, that living 

 substance contains in itself a certain even though a very slight 

 quantity of oxygen, which in low temperature is greater, in a 

 high temperature less, the recovery from narcosis, when oxygen 

 is withheld, is not at all surprising. The comparatively rapid 

 setting in of depression in narcosis finds a simple explanation in 

 the violent manner in which the oxydative breaking down, not- 

 withstanding the presence of oxygen, is suddenly suppressed by 

 the flooding by the narcotic. Finally, this view receives unlooked- 

 for support by a group of facts which at the first glance would 

 appear to bear no relation whatever to the process of narcosis. 



In a series of investigations on the mechanism of movement in 

 naked protoplasm,^ I have pointed out the role played by oxygen 

 in the genesis of the amoeboid protoplasm movement. We can 

 distinguish two antagonistic phases in the movement of amoeboid 

 cells, the expansion phase and the contraction phase. The first 

 consists in an increase, the latter in a diminution of the surface, 

 the mass remaining the same. The expansion phase is manifested 



I Max Verworn: "Die physiologische Bedeutung des Zellkerns." Pfliigers Arch. 



Bd. 51, 1891. 



The same: "Die Bewegung der lebendigen Substanz. Eine vergleichend- physiolo- 

 gische Untersuchung der Contractionserscheinungen." Jena 1892. 



The same: "Allgemeine Physiologie." V Auflage. Jena 1909. In the last place 

 the same theory of the contraction movements with some new corrections is described. 



