346 EXPERIMENT STATION RECOED, 



The oak mildew, E. Griffon and C. :Maublanc {B.ul. Trimest. ^oc. My col. 

 France. 2.j (I90i)), So. 1, pp. 37-50; uhs. in Rev. Sci. [Paris], 47 (1909), II, 

 :No. 1, pp. 20, 21).— Au account is given of tlie oak mildew, wliicli prevailed in 

 forests of France and otlier parts of Europe in 1907 and wliich became espe- 

 cially noticeable in 1908. Tlie autliors show that, contrary to previous observa- 

 tions, the American species of oak are subject to this mildew, and that it does 

 not seem to be especially limited to oaks but also attacks the beech, elm, and 

 chestnut. 



From the botanical standpoint, the mildew is of interest, and a number of 

 writers have suggested its relationship to various species of Erysiphacefe, 

 particularly Wicrosphwra alni and PhylJactinia corylea. The authors consider 

 the relationship between the oidium form and the Microsphiera as very doubtful 

 and that its affinity with Phyllactinia is not proved. They seem to favor the 

 opinion that it can not be safely associated with any of the known species of 

 Erysiphace:P. 



The origin of the invasion of the mildi'w is discussed at some length. The 

 authors state that opinions seem to differ as to whether it is an indigenous 

 species which has made an unaccountable development or whether it is an 

 introduced fungus, like the grape mildew, rot. etc. 



A disease of Zizyphus baclei, P. Hariot and N. Patouillard (Bui. Trimest. 

 Soc. Mycol. France. 25 {1909), Xo. 1, pp. 13, 1!,; Rev. Sci. [Paris], 1,7 (1909). I, 

 Xo. 2Ji, p. 758). — An account is given of the occurrence of a fungus upon the 

 fruits of Z. haclei in Africa. The fruits were badly deformed and covered with 

 a yellowish white powder. The fungus was determined and is described by the 

 authors under the name Coniodictyum cJicvalicri u. sp. 



ECONOMIC ZOOLOGY— ENTOMOLOGY. 



The brown rat in the United States, I). E. Lantz (U. S. Dcpt. Ayr., Bur. 

 Biol. Survey Bui. 33, pp. 5'i, pis. 3, figs. .'/). — The author describes the rat as the 

 worst mammalian pest known to man. Its depredations throughout the world 

 result in losses amounting to hundreds of millions of dollars annually. 



After discussing the distribution of the genus Mus in America, the history of 

 the brown rat and the habits of rats in general are taken up. The damage by 

 rats is considered under the headings of grains, poultry and eggs, game and 

 other birds, fruits and vegetables, merchandise in stores and warehouses, flowers 

 and bull)s. fires, damage to buildings and furniture, and miscellaneous damage. 

 The part that the pest plays in the transmission of bubonic plague is briefly 

 reviewed. Trichinosis among swine is probably perpetuated entirely by rats. 

 The probability that many disease germs adhere to rats' feet and are carried 

 to places where they threaten human health is mentioned. Ptomaines are some- 

 times said to be conveyed to meats or other human foods in this way. Hygienic 

 considerations are stated to furnish the strongest argument for the extermina- 

 tion of rats. 



The more important means of fighting rats are discussed at some length 

 under the captions, natural enemies of the rat, rat-proof construction of build- 

 ings, keeping food from rats, driving away rats, and destroying rats, including 

 trapping, poisoning, and contagious diseases. The author has drawn a summary 

 of the more important aids in limiting the number of rats and reducing the 

 losses from their depredations, which is as follows : 



" (I) Protection of our native hawks, owls, and smaller predatory mam- 

 mals — the natural enemies of rats. 



