480 Forestry Quarterly. 



Forstrat Seitner gives a lengthy account. 

 New with illustrations, of the bark beetle, which 



Genus has Pimis ceinbra for host plant. While 



of this beetle had formerly been supposed to 



Bark Beetles. be Polygraphus poUgraphus L., specific on 

 spruce, Seitner adduces features to show 

 that this is not only a different species, but should be made into 

 a new genus which he calls Pseudopolygraphus. The character 

 of the galleries and breeding chambers is curious and entirely 

 different from those of any other European species ; the beetles 

 have distinctive features. A full description is given. Inci- 

 dentally, the occurrence of Polygraphus grandiclava on Pinns 

 strobus as well as on ceinbra and on cherry is mentioned, and 

 an interbreeding of various bark beetle species suggested. 



Bemerkungcn zur Gattung Polygraphus und Aufstellung der Gaftnng 

 Pseudopolygraphus n. gen. Centralblatt f. d. g. Forstwesen. March, 

 1911, pp. 99-109. 



SOIL, WATER AND CLIMATE. 



A further interesting contribution regard- 

 Relative ing influence of litter on water conditions 



Soil of the soil comes from the long continued 



Humidity experiments carried on by the Austrian 



and Experiment Station. The first contribution 



Moss cover. was briefed in F. Q. Vol. IV, p. 161. Now 

 Dr. Wallenbock reports additional data 

 corroborative of former results and discusses also methods of 

 procedure. He develops the idea of the "relative soil humi- 

 dity," a conception similar to relative air humidity, namely the 

 percentic relation of the actual water contents to the absolute 

 water capacity of the soil, with which the loose terms based on 

 individual notions and judgment, wet, moist, fresh, dry, arid, 

 might find a more precise expression and conveying more clear- 

 ly than weight or volume per cent, of soil humidity the fact 

 whether a wet or dry soil is under consideration. 



Without going into the interesting details of method and 

 results, we may summarize the experiences. In dry years, the 

 area covered with moss dries out more slowly than the one that 

 is yearly deprived of its cover by raking, but light sum- 

 mer rains do not become available because the moss 



