172 EXPERIMENT STATION. [Jan. 



stiumliitiii^' tlic host to a more iil»iiii<laiit llow. The iiivccliuiii 

 of these fungi penetrate every portion of the gum, antl their 

 fungous threads may be seen even penetrating the host itself. 



On the Fruit-hearing Wood. 



The gum flow is almost without exception found at the base 

 of the pedicle hearing diseased fruit. These gummy masses 

 may be confined to a small area in the region of the pedicle, or 

 may extend some little distance below and above the pedicle, 

 sometimes becoming so bad as to entirely girdle the branch, thus 

 killing the entire distal portion. AVhen this happens it is best 

 to cut the diseased mendjcr off some two or three inches below 

 the gummy area. I believe this gum flow is first caused on 

 these small branches by the brown rot fungus, which is, without 

 an exception, found on the fruit attached to the diseased pedicle. 

 But as soon as this fungus causes the flow of gum the Cladospo- 

 rlum and AUernaria come in, as in the case of the injuries on 

 the trunks and large branches. After the above fungi, CJadospo- 

 rium and Alternaria, get a foothold, it would seem that the 

 brown rot fungus is less noticeable. Monilia is often to be 

 found in these gummy masses, but in masses containing Clad- 

 osporium and AUernaria this fungus has been found very spar- 

 ingly. These masses become soft during the damp spring 

 weather, and are usually washed to the ground by rains. 



Appearance of Cladosporium and AUernaria nnder the Above 



Environrnent. 

 At first the gummy mass is light in color, but after it remains 

 on the tree some time it becomes browned and blackened. On 

 sectioning one of these masses it is found that the darkened area 

 is near the surface, due to the formation of dark, thick-walled 

 cells, while farther in the mycelium becomes gradually lighter 

 in color, until nearly colorless at the center. On inoculating 

 branches of peach trees with the conidial form of Cladosporium 

 grown on prune agar it was found that some little time after- 

 wards a greenish growth of Cladosporium appeared. After the 

 spores had disappeared there soon appeared small, tear-like 

 drops, which, as the season advanced, grew larger and darker 



