BiiAx Anthracnosk 



293 



which it Hves. It has a thread-hke mycelium that grows into the tissue 

 of the bean to obtain food for its growth and development and it produces 

 spores that serve the purpose of seeds by which it spreads to healthy 

 beans and so reproduces itself. In fighting the anthracnose fungus, 

 we are fighting a parasitic weed, in its habits not greatly unlike the 

 dodder which often destroys alfalfa." 



Anrtiracnose Canker 



Anthracnose Spores 

 much rnQqiiified 



Bean Pod 

 Cut" Across 



Starcll Grains 



Fig. 221. — Showing the relation of the anthracnose fungus to the tissues of tlte bean. 

 To the left above is a diagram of a section across a bean pcd through an anthracnose 

 canker. The large drawing below is a much enlarged view of a portion of this same 

 section. It is largely diagrammatic. It shows how the mycelial threads of the fungus 

 m.ay penetrate the seed coat and enter the starchy tissue of the seed, there to remain 

 dormant until the following season. On the left of the large drawing is shown a 

 spore germinating and penetrating the epidermis. This germ tube branches, spreads 

 through the tissues of the pod, and so gives rise to a new spot or canker. To the right 

 above is shown a magnified view of some of the spores of the anthracnose fungus. 

 One has germinated. (Original.) 



"The fungus itself is too minute to be seen by the unaided eye. This 

 makes an understanding of its nature and ways of life rather difhcult, 

 but the picture of the parasite as shown in Fig. 221 will help to make 

 clear the discussion of the disease. Study the picture carefully before 

 reading the following account," 



"It is from the attack of the disease on the pods that the most direct 

 and apparent damage to the crop results. During the time of blossom- 



