^ Pilzkrankheiten der Pflanzen 
309 
Coons, G. H., S ome investigations of the Cedar rust fungus, 
Gymnosporangium J unifier i-vir ginianae (Nebraska Agr. Exp. 
Stat. Rept, 1912, 25, 215—245; pi. 1—3). 
After a review of work on the ejection of spores in the Basidio- 
mycetes, the author takes up the life history of the Cedar rust fungus. 
The fungus has its aecia on Malus and Pyrus , with telia on Junifierus 
virginiana. Sporidia sown in drops of water on wealthy apple leaves 
under a bell jar gave greater infection on the upper surface than the 
lower, since there are few if any stomata on the upper surface this is 
taken as an indication that the epidermis is penetrated. The author 
agrees with Heald that the mycelium is perennial in Junifierus , and 
believes, without experimental evidence, that infection takes place through 
the leaf. Teliospores are formed in December. On germination they 
produce one or two germ tubes, but never four, the process requiring 6 
to 15 hours, but under certain conditions of moisture or temperature, 
neither germ tubes or sporidia form; cold wet weather causes abnormal 
forms, while coal gas and C0. 2 prevent germination. Oxygen-free air 
produces germ tubes eight to ten times normal length. Frequently a 
germ tube produced three sporidia and the fourth tube elongated and 
penetrated the epidermis directly, making a quicker infection that spores. 
Cedar galls vary from 1 to 50 mm in diameter, with sori from 1 to 
2 mm apart when dry. 
Spore prints were found convenient in securing spores for pure 
culture. Spore discharge was studied by Buller’s method, using a con¬ 
centrated beam of light, and was found to continue for two hours. Galls 
five months old did not revive. The spores are adhesive and are ejected 
from the basidia for a distance of 13 to 18 times their length, in the 
same manner as in the Hymenomycetes. Neither light, temperature 
or humidity appeared to affect the discharge, but chloroform and 
ether stopped it immediately; ejection is a result of turgor relations. 
The paper closes with a brief review of the phyllogeny of the 
Uredinales and cytological work on the Basidiomycetes , emphasizing the 
relation existing between the Uredinales and Hymenomycetes. 
C. J. Humphrey (Madison, Wise.). 
PAMMEL, L. H., Some fungus diseases of trees (Iowa Acad, of 
Science 1911, 25—33; 3 pi., 1 fig.) 
The paper gives popular notes on a number of forest fungi. Fames 
igniarius (L.) is said to seriously affect Pofiulus tremuloides in the 
Rocky Mts. Pleur otus ulmarius Bull, is common in Iowa as a 
wound parasite of Acer Negundo and Tilia americana. Polystictus ver¬ 
sicolor (L.) is likewise very common on various hardwoods, and is often 
considered as a root rot. Armillaria mellea (Vahl.) occurs in Iowa 
around oak stumps, and occasionally around living oak trees, when it 
stunts and gradually kills them. 
The spot disease of Butternut and Black Walnut, due to 
Gnomonia lefitostyla (Fr.) has been under observation for twenty years. 
It is more serious than ordinarily supposed, and often defoliates the trees 
in the latter part of August. 
A Tafihrina species, apparently new to science, is reported on Acer 
grandidentatum in Utah. The trees were often entirely defoliated. The 
