ENDOTHIA PARASITICA AND RELATED SPECIES. 67 



The specimen collected by Besley on Quercus prinus showed the fan- 

 shaped mats of mycelium typical of E. parasitica on Castanea spe- 

 cies. The fungus had apparently girdled the tree. The specimen on 

 Quercus alba, collected by Detwiler, was similar to one on Quercus 

 prinus in appearance and came from a dead tree which had appar- 

 ently been killed by the growth of the fungus. The specimens on 

 Acer sp. and on Quercus alba were received in the spring of 1914, 

 and cultures isolated from them were used in making inoculations 

 for the purpose of determining whether the fungus had either lost 

 or gained in virulence by passing through other hosts. 



INOCULATION EXPERIMENTS. 



The cultures secured from Acer and Quercus, together with one 

 made from Castanea at about the same time, were inoculated into 

 three separate sprouts of Acer rubrum, Castanea dentaia^ and Quer- 

 cus prinus. The sprouts chosen were of nearly the same size, 2 

 inches in diameter, and similarly situated, and each was inoculated 

 in five places, with two check cuts above. The inoculations were 

 made the usual way on March 31, 1914. and were examined at least 

 once a month during the summer. 



None of the inoculations on Quercus produced any growth what- 

 ever. On Acer the inoculations with the culture from Quercus all 

 failed to develop; one of the inoculations with the culture from 

 Acer showed a few pycnidia, while four of the inoculations with 

 material from the chestnut developed a few pycnidia. On Castanea 

 the three series of inoculations were almost identical, every inocula- 

 tion producing a typical canker. 



Of course, these inoculations are too few to be conclusive, but it 

 is evident that there was no decrease in virulence on the chestnut 

 in passing through Acer or Quercus and that no particular affinity 

 for either Acer or Quercus was gained. On the maple, in fact, the 

 culture direct from chestnut produced the most growth. 



In addition to those listed above, numerous inoculations were made 

 in order to determine whether Endothia parasitica had any parasitic 

 tendencies on other deciduous hosts. 



These inoculations were all made during the spring of 1914 by 

 the usual method of cutting well through the bark and inserting 

 mycelium and spores from a pure culture, usually on corn meal. 

 The wounds were then wet, some bound with wet cotton, others with 

 paraffin paper, and about half were left unwrapped. 



Seven or more inoculations were made on April 4 in Maryland on 

 A Inus rugosa, Betula nigra, Oarpinus caroliniana, Fagus grandifolia, 

 Kalmia latifolia, Liriodendron tidipifera, and Liquidambar styraci- 

 flua, none of which developed. Inoculations were also made on April 



