Pkthybkidck and Lafferty — A Disease of Flax Seedlings. 379 



were scattered through the crop in a field, each would probably serve as a 

 centre from which the disease would radiate during the growing season, 

 provided the weather conditions were favourable for the spread of the 

 fungus. 



The experiment was repeated, and alongside of it another one was carried 

 out in which hydrogen peroxide (20 vols.) was used as the disinfectant. The 

 strength of formalin used was one part (40 per cent.) in four hundred of water. 

 After steeping, the one hundred seeds used in all cases were allowed to become 

 air-dry before sowing. The pots and soil used were carefully sterilized, and 

 the former were kept under bell-jars during the experiment, which lasted for 

 twenty-one days. Two controls, consisting of one hundred untreated seeds in 

 each case, were used, and the disease appeared first in these, namely, twelve 

 days after the sowing of the seed. The seedlings were very closely examined 

 each day (except on the sixteenth), and any showing the disease were carefully 

 removed at once. The results are summarized in the following table : — 



As in the previous experiments, steeping the infected seed in weak 

 formaldehyde solution for several minutes totally eliminated the disease, but 

 depressed the germination percentage and resulted in the production of injured 

 seedlings, Steeping for a shorter period greatly reduced the disease, but did 

 not totally eliminate it. It had a less serious effect on the total germination, 

 and caused only a very slight retardation in growth of the seedlings. 



