Periodical Literature. 269 



were killed in 1909, injury being greatest at the higher elevations 

 and on northerly exposures. The effect was more severe on older 

 needles, or older parts of the needles- In some cases buds were 

 injured. The selective injury to the needles is ascribed to ina- 

 bility of the older ones to supply transpiration of water. In the 

 case of Picea canadensis the less vigorous branches were killed ; 

 while the latest growth of birch and aspen was considerably in- 

 jured. 



The injury appears to be due to very low temperatures, fol- 

 lowed by a strong warm wind with rise in temperature up to 

 57° F., resulting in rapid loss of water while the limbs and 

 trunks were still frozen. 



Similar injury occurred in Colorado and many other places, 

 and notes are also given on the winter-killing of different species 

 in Nebraska during 1909-10, in which the effect was entirely 

 different from the "chinook" injury. 



Notes on winter-killing of forest trees. University of Nebraska Forest 

 Club Annual. April, 1912. Pp. 30-50. 



Investigations by Craighead of the Bureau 

 Chestnut of Entomology during the summer of 1912 



Blight on the spread of the chestnut blight show 



and that certain insects destroy many of the 



Insects. pycnidia and perithecia of the infesting 



fungus. Five species are noted, among 

 which is the chestnut borer (Agrilus bilineattis). In some locali- 

 ties 50 to 75 per cent, of the pustules were eaten, and on certain 

 badly diseased trees practically all were destroyed. The author 

 believes that the insects are acquiring a taste for the fungus 

 which may play an important part in controlling the disease. 

 Nothing is said, however, as to the role they play in carrying the 

 spores about on their bodies. 



Insects contributing to the control of the chestnut blight disease. 

 Science. December, 1912. P. 825. 



Oueritet sketches the development of the 

 Oak epidemic of oak mildew in Europe since its 



Mildew- beginning in 1907. While the disease oc- 



curs in nature largely on the native oaks, 

 beech, elm, ash, maple, birch, elder, and mountain ash are said 

 to be susceptible, at least to artificial infection, while alder. 



