206 Report of the Botanist or the 



with a white mycelium. Pieces of the fungus covered roots were 

 stuck into wet sand in a sterilized Mason fruit jar. In this culture 

 tho white mycelium was gradually replaced by numerous light 

 brown rhizomorphs and after three months the roots became 

 thickly covered with the conidial fructification of Dematophora. 

 The sporophores measured from one to one and one-half millimeters 

 in height. To the unaided eye they appeared to be short, brown 

 stalks with colorless or purple ovoid knobs on their ends. Under 

 the microscope the brown stalks proved to be compound sporo- 

 phores, composed of brown, septate hyphse; and the colorless, 

 ovoid knobs were composed of small, colorless, ovoid spores borne 

 on the branched free ends of these hyphse. The fungus agreed 

 closely with Hartig's description^ of Dematophora necatrix except 

 that the hyphse composing the rhizomorphs were destitue of pyri- 

 form swellings at the septa. 



The Dematophora, and not the walnut tree, was probably the 

 cause of the death of the vines. Some of the dead vines were 

 certainly beyond the reach of the roots and shade of the tree. 

 The soil was a sandy loam and well drained. See Gooseberry 

 Root Rot, page 203. 



CHLOROSIS OR YELLOW FOLIAGE. 



In an old but well cared for vineyard at Coxsackie we found 

 many plants showing yellow foliage by June 1. The yellow 

 leaves were much dwarfed. Sometimes the whole vine was af- 

 fected, but it often happened that a part of a vine would be di- 

 seased and a part healthy. According to the owner, affected canes 

 die the following winter. When all of the canes are affected and 

 die, new canes come up from the root. The affected plants 

 were scattered irregularly over the vineyard. 



Chlorosis may be due to several causes. ITot having had oppor- 



24 Hartig, R. Dematophora necatrix, n. sp. Untersuchungen aus d. forst- 

 botan. Institut zu Miinchen. Ill, '1883. 



