Notes and Brief Articles 
315 
of stems and roots, etc., the nature of the infection being essen- 
tially the same in different plants. 
Two excellent illustrated papers on the Polyporaceae have been 
published during the past year by Mr. L. O. Overholts. The first 
is a treatment of the Polyporaceae of the middle^western United 
States, which appeared in Washington University Studies for 
July, 1915. The second, entitled comparative studies of the 
Polyporaceae, was printed in the Annals of the Missouri Botani- 
cal Garden for November, 1915. Students of this family of 
fungi should not fail to add these papers to their library. 
Professor T. Petch has been studying the sclerotia of Lentinus 
found on stumps of Hevea, and he says that in addition to species 
possessing a true sclerotium, there appear to be others whose 
mycelium merely binds together the earth in a large compact 
mass, while Lentinus similis and L. infundibtdiformis exhibit a 
third type in which the skeleton of the pseudosclerotium consists 
of the wood of the host plant. It is considered as still an open 
question whether these types are definitely associated with dif- 
ferent species of Lentinus or are merely stages which may be 
assumed by the sclerotium in any given species. 
In an article published in the July number of the American 
Journal of Botany, W. B. McDougall makes the following state- 
ment regarding mycorrhizal relations existing between mush- 
rooms and the roots of forest trees : 
“ Three of the species of trees used in the present investigation 
produce ectotrophic mycorrhizas, the oak (Quercus) , hickory 
(Carya) and linden (Tilia). The mycorrhizas of the oak are 
due to Russula foetentula Pk., those of the linden to Scleroderma 
vulgare Fr., and those of the hickory probably to Laccaria ochro- 
purpurea (Berk.) Pk., though this last has not been definitely 
proven. In all of these cases no mycorrhizas were formed in the 
spring, but after the first of July mycorrhizas were formed when- 
ever the roots were growing well.” 
Dr. E. A. Burt’s valuable articles on the Thelephoraceae of 
North America are appearing regularly in the Annals of the Mis- 
