298 Bulletin 255. 



Considering the manner in which the fungus finds its way into the seed, 

 it seems evident that if no spots are to be found on the pods, none of the 

 seed within will be diseased. That is to say, healthy pods contain healthy 

 seed. It is just possible that we may have one exception to this, though, 

 so far as the writer has been able to find there is no positive evidence 

 in favor of such an exception, namely, that infection of the seed may 

 take place by way of the blossom, without any evidence of such infection 

 on the pod or in fact in the seed itself at maturity. Blossom infection 

 is known to take place in a number of fungous diseases, but the nature 

 of this disease is such that, that hardly seems probable. It has been 

 pointed out by some that the sudden and destructive appearance of 

 the disease in pods at a certain stage in their development, seems to 

 indicate that something of this sort takes place. It is a common observa- 

 tion also, that pods picked in the evening apparently entirely free from 

 the disease will sometimes be found the following morning to be very 

 badly spotted, and shippers of garden truck have often suffered serious 

 losses from the development of this disease in snap beans during the 

 short time required for the transportation from fields to market. Never- 

 theless, while the writer has seen several cases of this nature, he has 

 never been satisfied that the infection was not due to the ordinary inocula- 

 tion of the pods by spores from occasional diseased pods among the 

 healthy; the rapid development of the disease in such cases being due 

 ordinarily to favorable conditions of temperature and moisture. Sur- 

 prisingly enough in the cases of this kind of which the writer has known, 

 a relatively low temperature, particularly a sudden drop in the tempera- 

 ture seems to have been the controlling factor. If then, the principle 

 laid down, that healthy pods contain healthy seeds, holds true, it seems 

 that we have a fairly easy means of obtaining clean seed. During the 

 season of 1907 the writer undertook the selection of clean pods of a 

 number of varieties of beans in order to determine whether it would be 

 practical and effective. On account of the large amount of work on 

 hand during the autumn, only a very small amount of seed of a few 

 varieties was thus obtained. Perhaps, enough to plant half an acre of 

 a total of five or six varieties. Some germination tests of the seed thus 

 obtained were made during the winter of 1907-08, and in no case was 

 any anthracnose discovered. This seed has been planted during the 

 season of 1908, to see if it will give a perfectly healthy crop. However, 

 the conditions under which the seed of this year were collected were 

 far from favorable. In the first place, the selection and sorting of the 

 seed had to be left largely to students or inexperienced assistants; 

 in the second place, the season was so far advanced when the selection 



