210 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 12-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 CO, production and the O, 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 
UNTREATED TISSUE ETHYLENE TREATED 
Ames iri 
: » iF 
62 cc. CO: cc. O2 “ aon. fy cc. CO: cc. O2 o 
6a - centage 
o, (by vol.) 
3 | Epicotyls only ..| 0.2185 | 0.3664 | 0.66 | 0.0002 | 0.2449 | 0.3030 | 0.81 
6 = esas 2255 | 0.3419 | 0.66 re 0.1703 | 0.2898 | 0.61 
6 | Entire seedling..} 0.4138 | 0.6069 | 0.69 xe: 0.3780 | 0.5744 | 0.66 
12 a Se [ 0.3950 10,5345. 10770 oe 0.3197 | 0.4668 | 0.69 
24 hy i DO Se6e 1-0, 4100 | 0, Od “  *! 0.3127 | 0.3873 | 0.81 
24 | Epicotyls only ..| 0.3145 | 0.4025 | 0.78 | 0.01 0.3380 | 0.4086 | 0.84 
48 | Entire seedling..| 0.2501 | 0.2897 | 0.86 | 0.0002 | 0.2404 | 0.2869 | 0.85 
72 a o>) Oat) 0; 2360 10.20 eS 0.2610 | 0.2212 | 1.04 
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 o.81 seems extremely 
high in consideration of the 0.66 ratio of the control, and particu- 
larly of the o.61 ratio of the 6-hour ethylene culture. However, 
IRVING (12) in her study of the effects of chloroform on barley 
leaves found that “medium” doses cause a large initial outburst 
of CO, 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 o.ooo1 per cent ethy- 
lene concentration used is equivalent in its physiological effects 
to the so-called “strong”? concentrations of those anaesthetics, 
