270 Forestry Quarterly. 



chestnut, and American oak have so far proved resistant. The 

 native Quercus robur is said to be less susceptible than its close 

 relative Q. pedunculata, on account of its thicker coriaceous 

 leaves- 



The development of the disease from spores in the spring is 

 described, the injury resulting from stunting and premature 

 death of the foliage and inability of the immature twigs to with- 

 stand winter freezes. One to two year nursery trees may be 

 killed outright or lose their commercial value. Under such con- 

 ditions, finely powdered sulphur has been found most effica- 

 cious in controlling the disease. Certain sprays are also noted. 



The drier climate of Central Europe may account for the slow 

 spread of the disease in that region. 



Regarding the question of overwintering of the fungus a 

 Dutch article by Poeteren has recently been translated into 

 French. This throws further light on the subject and supports 

 and modifies Neger's theory that the organism survives the win- 

 ter in the buds in the mycelial stage. The number of shoots 

 bearing infected buds is variable, but relatively small. Such 

 shoots are termed "mother shoots," as it is found that they serve 

 as the primary source of spring infection, the fungus develop- 

 ing with the bud. Upon these few newly developed shoots con- 

 idia form which spread the secondary infection to other parts of 

 the tree. 



Upon this method of hibernation protective measures are based. 

 These involve the removal of "mother shoots" at the time the 

 buds open, so as to avoid the secondary infection. This can 

 probably be carried out in nurseries, also possibly on coppice 

 oak, and supplements spraying, which is so commonly employed 

 against the disease. 



Le blanc du chctie. Bulletin Societe centrale forestiere de Belgique 

 October, igi2. Pp. 577-588. 



De ovcrwintcringen bestrijidng van eenige meeldauzwammen. Tijdschr. 

 over Plantenz. 18, 85-95 19^2 and Le blanc du chene- Bui. Soc. cent, forest. 

 Belg. December, 1912. Pp. 750-759. 



Pythiinn debaryanum is said by Hartley to 



Damping-off be the most dangerous parasite in western 



Fungi. nurseries, although Rhizoctonia, fusarium 



and probably Trichoderma lignorum also 



cause damping-off. Rhizoctonia loses its parasitism in culture, 



