260 BOTANICAL GAZETTE [ APRIL 
stored food material of the endosperm, or it may be that the gas 
exerts influence directly or indirectly upon two or more of these 
seed parts. If the grain or seeds are dry the influence of the 
gas is far less marked than if they are moist, and the drier 
they are the less the influence of the gas. It would seem that 
the gas exerts its influence, therefore, through the medium of 
the moisture contained in the seeds and in the seedlings. Even 
in older plants it is the more succulent parts that are most 
readily affected by the gas. The seed coats serve more or less 
as a protection to the inner seed parts, for as soon as the seed- 
lings escape from the seed coats they are more seriously affected 
by the gas, and if the charge is sufficiently strong, the seedlings 
refuse to grow almost as soon as they leave the seed coats. Dry 
seeds are sufficiently resistant to the influence of hydrocyanic 
acid gas to be treated for several weeks with an atmosphere 
saturated with the gas without destroying their vitality. It 
would be impossible, however, to preserve even dry seeds indefi- 
nitely in any strength of the gas, since it eventually penetrates 
them and impairs and finally destroys their vitality. If the 
seeds are damp they are much more susceptible to the influence 
of the gas, and should not remain more than two or three hours 
in gas of sufficient strength to destroy animal life. If for any 
reason it becomes necessary for the damp seeds to remain for a 
longer time in the gas, the injury will be materially lessened by 
thoroughly washing the seeds in water as soon as they are 
removed. 
The fact that damp seeds are more susceptible to hydro- 
cyanic acid gas than dry seeds would indicate that the gas is 
taken up more readily by the damp seeds, and the same is true 
of other gases. 
EFFECT OF HYDROCYANIC ACID GAS ON SEEDS FOR FOOD. 
Dry seeds.— Only a few experiments have been performed 
along this line, but probably a sufficient number to determine 
the point in question, viz., whether dry seeds treated with 
hydrocyanic acid gas retain enough of the poison to make them 
