ECONOMIC ZOOLOGY — ENTOMOLOGY. 647 



New facts concerning the white pine blister rust, P. Spaulding ( U. S. Dept. 

 Agr. Bui. 116 (1914), pp. S).— In a previous publication (E. S. R., 29, p. 554), 

 the author presented information regarding the white pine blister rust up to 

 1913. In the present publication additional information is given based on 

 extensive investigations conducted during the summer and fall of 1913. This 

 includes an account of the work with infested white pine trees near Geneva, 

 N. Y., new outbreaks in northern Vermont, near Ipswich, Mass., and near 

 Meriden, Conn., observations on the wintering-over of the disease on Ribes, 

 Pinus excelsa as a host, spore distribution of Cronartium riMcola, and a tabular 

 account of the general results of inspections. 



The damping-off of coniferous seedlings, P. SPAtixDiNG (Phytopathology, 4 

 {1914), No. 2, pp. 7-S-8S, pi. 1, figs. 2). — On account of the seriousness of damp- 

 iug-off of coniferous seedlings, the author has made a study of methods of 

 control, particularly that of soil sterilization. 



The dampiug-off of coniferous seedlings is due to a number of organisms, 

 among them Fusarium, Pythium, and Rhizoctonia. In the experiments reported, 

 tests were made of a number of fungicides for soil treatment as well as modifi- 

 cations of nursery methods. The experimental work indicates that soil steriliza- 

 tion sufficient to prevent damping-off is effectively accomplished with formalin 

 (1 oz. to 1 gal. water, or stronger), sulphuric acid (1 oz. to 1 gal. water, or 

 stronger), and rather dilute ammonium copper carbonate. These chemicals 

 should be applied before seedling, as no chemical was found that was efi:ective 

 in stopping outbreaks of the disease after germination. Weak formalin applied 

 after germination of seeds was found worse than useless, as it destroyed many 

 of the young plants. The quality of the seed was found to have something 

 to do with damping-off, as hght weight, poorly filled seed produced weak 

 seedlings, which were longer in germinating and were very subject to this 

 disease. 



A bibliography of the subject is appended. 



Preliminary tests of disinfectants in controlling damping-off in various 

 nursery soils, C. Habtley and T. C. Merrill {Phytopathology, 4 {1914), No. 2, 

 pp. 89-92). — The results are given of cooperative experiments for the control of 

 damping-off of pine seedlings, caused mainly by Pythium debaryamuii and 

 Fusarium sp. In the experiments copper sulphate, zinc chlorid, formalin, and 

 sulphuric, nitric, and hydrochloric acids have been tested. 



So far the best results on most soils have been secured with sulphuric acid. 

 This has proved more successful than heat, where both have been tested, and 

 it also protects the soil against reinfection. In an experiment in which air- 

 slaked lime was applied following the acid disinfection, the treatment seemed 

 to be successful without injury to the plant, but it allowed reinfection. For 

 soils on which sulphuric acid is not an efficient disinfectant, zinc chlorid and 

 copper sulphate seemed to possess greater efficiency than formalin. 



ECONOMIC ZOOLOGY— ENTOMOLOGY. 



Revision of the American harvest mice (genus Reithrodontomys), A. H. 

 Howell {U. S. Dept. Agr., Bur. Biol. Survey, North American Fauna No. 36 

 {1914), PP- 94, pis. 7, figs. 6). — In this revision the author recognizes 58 species 

 and subspecies as belonging to the genus Reithrodontomys, of which seven are 

 described as new. 



The American harvest mice are said to occur abundantly in or near meadows 

 and cultivated lands over a large part of the United States. While their exact 

 economic relation is still little known they belong to a group of mammals 



