BOTANICAL GAZETTE 



[SEPTEMBER 



In table X are the results of the analyses. Each set of fig- 

 ures represents the average of a number of analyses; for example, 

 the 1 2-hour cultures are from 16 analyses upon gas of 3 different 

 cultures. The results plainly show a general depression of respira- 

 tion by ethylene, both in the C0 2 production and the 2 absorption. 

 The respiratory ratio gradually increases with the time in both 

 tissues, an increase which probably is due to the lowering of the 



TABLE X 



Respiratory changes 



oxygen pressure. In the 3-hour culture with ethylene the ratio 

 is very large. The result, as it stands, comes from an excessive 

 production of carbon dioxide. This ratio of 0.81 seems extremely 

 high in consideration of the 0.66 ratio of the control, and particu- 

 larly of the 0.61 ratio of the 6-hour ethylene culture. However, 

 Irving (12) in her stud)' of the effects of chloroform on barley 

 leaves found that "medium" doses cause a large initial outburst 

 of C0 2 quickly followed by a depression. 



Conclusion 



The results of the present study seem to indicate that the general 

 effect of ethylene on plant metabolism is exactly comparable to 

 the effects of the common anaesthetics, chloroform, ether, etc., as 

 reported by other workers. Also, that the 0.0001 per cent ethy- 

 lene concentration used is equivalent in its physiological effects 

 to the so-called "strong" concentrations of those anaesthetics, 



