
254 BOTANICAL GAZETTE [ APRIL 
note that the small charge of only 0.0038" of KCN retarded the 
germination but a few hours as compared with the retardation 
produced by the same charge of gas when the seeds were soaked 
for twenty-four hours. It is likewise a noteworthy fact that 
when the seeds were soaked but twelve hours they were much 
more resistant to the influence of hydrocyanic acid gas, as 
evidenced by the fact that at least a few of the seeds were able 
to germinate in as much as 0.0508" of KCN per cubic foot. The 
subsequent behavior of the seedlings was the same as, in the 
preceding case, 7. e., there was little or no growth after the 
plant escaped from the seed coats. In general it was found that 
the shorter time the seeds were soaked the more resistant they 
were to the influence of the gas. 
TABLE V. 
Same as table III, except that the seeds were soaked for a longer time before placing 



Amount of KCN per cubic foot ace of Time — ae pepeua mH 
es germination germination| of seedlings 
511,513 Aueestear cuts g Siar oes er 36 hours | 20 hours 100 normal 
eee ae tee 60 | slight 
Si 2A ENCE oN Ae 36." no germination Oo Rea 
SE cc se ae ear cio 36 e it ‘“s Oo 
GOGO: seni ee ena: 36 “ » es 
0.075 36 73 ‘“ ké a 






In these experiments it will be seen that the extra amount of 
soaking caused the seeds to germinate more readily than they 
would have done had they been soaked but twenty-four hours, 
both in the case of the control experiments and in the experi- 
ments in which but 0.0038" of KCN was used. However, the 
seeds did not germinate as readily as they did when soaked but 
twelve hours, nor was the percentage of germination so high as in 
either of the preceding cases. It is probable that the germination 
took place more quickly than in the experiments recorded in 
table III, because the seeds were more advanced before they 
were removed from the water and placed in the gas. In all 
cases the seeds were extremely sensitive and made but very 
tS ee 
