246 EXPEKIMENT STATION BECOED. 



Observations on the life history of Ustilago vaillantii, Ivy Massee {Jour. 

 Econ. Biol, 9 {1911}), No. 1, pp. 9-U, pi. i).— The author states that U. vail- 

 lantii, found only on Liliacese, permanently infests its host in the seedling stage. 

 The fungus grows up from the bulb each year with the stem and produces in 

 the anthers and ovary spores which, after being dried, retain vitality for at 

 least three months. 



Phytopatholog'ical notes from North American forests, C. voN Tubeuf 

 {Natuno. Ztschr. Forst u. Landw., 12 (1914), ^o. 2, pp. 89-91, fig. i).— Report- 

 ing briefly a study of two species of Uredinese noted on a recent American tour, 

 the author names these Cceoma psettdotsugce douglam and JJredo chamwcyparidis 

 nutkwnsis, respectively. 



The morphology and life history of the chestnut blight fungus, P. J. 

 Andeeson {Penn. Chestnut Tree Blight Com. Bui. 7 (1913), pp. 44, Pls. 17). — 

 The results are given of a study on the morphology and life history of the 

 chestnut-blight fungus (Endothia parasitica) . 



Among the observations reported it is stated that the ascospores germinate 

 readily in water, while the pycnospores require a nutrient medium. The pycno- 

 spores germinate on the twigs of a large number of forest trees and also in 

 humus about the base of the trees. At summer temperatures the pycnospores 

 germinate in from 12 to 36 hours, while the ascospores germinate in from 2 to 

 12 houra Lower temperatures retard germination. The ascospores in the peri- 

 thecia and the pycnospores in the " horns " are said to retain their germiuative 

 power for at least a year. The longevity of the spores is diminished when they 

 are separated from each other or exposed to the air. Winter weather condi- 

 tions were found not to aflfect the vitality of either kind of spores or of the 

 mycelium. The author states that the mycelium does not invade the living 

 tissues as individual hyphse, but in flat fan-shaped mats. It continues to grow 

 in the bark even during the winter months, but with much more rapidity in 

 the summer season. The fungus, it is said, may be carried over in the bark 

 for a year or more by the mycelium even when the bark is kept quite dry. 



A bibliography is given. 



The death of chestnuts and oaks due to Armillaria mellea, W. H. Long 

 (U. 8. Dept. Agr. Bui. 89 (1914), PP- 9, pis. 2).— The results are given of a 

 study of chestnut and oak trees in New York and in North Carolina, from 

 which the author claims that chestnut timber in these two regions is deteriorat- 

 ing, as shown by the small annual increment during recent years, by the thin 

 sapwood, by the large percentage of diseased and stag-headed tops, as well as 

 by the number of dead and dying trees. The decline is considered probably due 

 to several factors, one of which is the root I'otting fungus A. mellea. This 

 fungus, it is claimed, can become an active parasite under favorable conditions, 

 especially on oaks and chestnuts, killing not only suppressed trees in the forest, 

 but those growing under more favorable conditions. The prevalence and ap- 

 parent destructiveness of this fungus seem to point to it as a very important 

 factor in the gradual recession of the chestnut timber in North Carolina. 



The chestnut bark fungus (Endothia parasitica) was not found present in 

 either of these localities. 



A preliminary contribution on the receptivity of oak for Oiidium, V. 

 EiVERA (Atti R. Accad. Lincei, Rend. CI. 8ci. Fis., Mat. c Nat., 5. ser., 22 (1913), 

 II, No. 4, pp. 168-173). — Reporting a study of Oklium on Quercus robur in 

 relation to attack from Oidium as affected by temperature, age, turgidity, and 

 functional activity of the leaAes, and rapidity of root absorption, the author 

 concludes that while mature leaves are resistant to this disease, rapidity of 

 growth favors attack. Young leaves kept in a very humid atmosphere in a con- 

 stant state of high turgidity are not very susceptible to attack. High temper- 



