98 Forestry Quarterly. 



green shoots and the aerial haustoria, leaving the plant only with 

 the wide-spread parasitic root-system, which thrives many years 

 without serious injury to the host. 



Whether the phloems of the parasite and host are in direct 

 connection was not worked out. 



Parasitism of Phoradendron juniperinum libocedri Engelm. Proceed. 

 Soc. Am. Foresters 7, March, 1912. Pp. 35-41. 



The discussion over the identity of the oak- 

 Oak mildew in Europe still wages. The opinion 



Mildew. of Arnaud & Foex, who first found the 



perfect stage and called it Microsphaera 

 extensa (Schw.) Burr., is challenged by Griffon & Maublanc. 

 Both authors have examined authentic specimens of American 

 Microsphaeras and compared them with the three known collec- 

 tions on European oaks and a mass of details is presented as to 

 the minor points in which they vary. 



As a result of the study Griffon & Maublanc hold that the 

 American species or forms on oak can be placed in two species 

 and one variety, as follows : 



1. M. abbreviata Pk. (=il/. densissima Cke. & Pk., M. quer- 

 cina Schw. et auct., M. alni of Salmon, in part). 



2. M. abbreviata Pk. var. calocladophora Atk. 



3. M. extensa Cke. & Pk. (=M. quercifia of authors, in part, 

 M. quercina var. extensa Atk., M. alni var. extensa Salm.). 



These are said to be distinct from the true M. alni, and also 

 from the three previously known European collections, hence the 

 authors propose the name of Microsphaera alphitoides Griff. & 

 Maubl. They suggest that the fungus was probably imported. 



Arnaud & Fopx reply to this in support of their former con- 

 tention and conclude with the statement that Microsphaera alphi- 

 toides is only a synonym of a species "already too richly sup- 

 plied with names." They still hold to their former view of the 

 fungus being indigenous. 



Les Microsphaera des Chenes. Bull. Soc. Myc. Fr. 28, April, 1912. 



Les Microsphaera des Chenes et les Peritheces du blanc du Chene. 

 Compt. Rend. Acad- Sci. 154, April 9, 1912. Pp. 935-538. 



Sur I'oiidium des Chenes. Compt. Rend. Acad. Sci. 154, May 13, 1912. 

 Pp. 1302- 1305. 



