I02 Forestry Quarterly. 



Investigations conducted by the author 

 Heart-rots in 191 2 on the condition of the oaks in 



of the Ozark National Forest and elsewhere 



Hardwood Trees, resulted in finding twenty different kinds 

 of heart-rot. Six of these have been for 

 the first time associated with the producing fungi, and an ac- 

 count of three of them is given in this paper. The number of 

 affected trees in some districts is very great — in one instance up 

 to 64.8 per cent of some thousands of oaks that had been felled 

 for commercial purposes. The infected trees were as a rule 

 old trees, and the fungi had gained entrance in general through 

 fire-scars. "So marked is this association of fire-scars with 

 heart-rots in the Ozarks that one could tell the areas in the 

 forest which had been most frequently burned over from the per- 

 centage of trees affected with heart-rots." 



The three types described are: (i) a pocketed or piped rot of 

 oak and chestnut caused by Polyporus pilofae Schw. ; (2) a 

 string and ray rot of the oak caused by P. berkeleyi Fries ; and 

 (3) a straw-colored rot of oak caused by P. frondosus Fries. 



J. H. F. 



Three Undescribed Heart-rots of Hardwood Trees, Especially Oak. 

 Journal of Agricultural Research, Vol. i, No. 2, 1913, pp. 109-128. 



Prof. Crocker and his assistants are car- 

 Toxicity ning on extensive experiments in gas in- 



of juries to vegetation at the University of 



Smoke. Chicago, and the present paper is the first 



of a series of articles to be published on the 

 subject. They find that chimney smoke is only slightly toxic to 

 the seedlings of sweet pea. 500 times less so than the smoke 

 from a loosely rolled paper cigarette. Injuries from coal smoke 

 are generally attributed to tars and oxides of sulphur, while 

 reduced carbon-bearing gases have never been considered as a 

 factor. The authors think, however, that carbon-bearing gases, 

 especially ethylene might be in sufficient concentration to do in- 

 jury and still be in too small quantities for detection by chemical 

 analysis. One part of this gas in 10 million of the atmosphere 

 inhib|^the growth of an etiolated epicotyl of the sweet pea. The 

 processes of civilization are continually adding to the ethylene in 



