362 



BOTANICAL GAZETTE 



APRIL 



more than doubled, but gradually decline. After i hour the rela- 

 tive rate of respiration was still above the normal. In this case 

 the time of death could not be determined. 



The experiments show that although the rate of respiration 

 may be maintained for a time after death, it gradually falls off 

 and eventually becomes very small. The question arises whether 

 this falling off is due to exhaustion of the supply of oxidizable 

 material or not. It is clear that when respiration has practically 

 ceased there is a considerable amount of organic material left, but 

 it is by no means certain that this material is such as to be easily 

 oxidized by the ordinary processes which produce CO2. On the 



TABLE VIII 

 Change in PH value of sea water produced by respiration of Laminaria during 



5 PERIODS (31.25 MIN. each) IN SEA WATER; BETWEEN SECOND 

 AND THIRD PERIODS MATERIAL FINELY MINCED 



other hand, we must consider the possibiHty that the production 

 of CO2 falls off because the supply of oxidizing enzymes is used up. 

 Various observers have found that these enzymes may be used up 

 (or inactivated) during oxidation (i, 9). If the process of oxida- 

 tion involves the cooperation (or successive action) of various 

 enzymes the inactivation of any one of them might bring the whole 

 process to a standstill. 



Warburg (21), as the result of extensive study, has come to the 

 conclusion that the rate of oxidation depends on the amount of 

 "structure" which the cell possesses. If the "structure" is par- 

 tially or completely destroyed the oxidation diminishes in propor- 



