No. 2, December, 1921] PATHOLOGY 111 



of the paper deals with the action of the sprays upon the host plant. After washing the 

 treated leaves of Viii^ with HCl, to remove adhering substances, they were found to have 

 absorbed detectable quantities of copper, calcium sulphate, and thiosulphate radicles. Cop- 

 per was found to be immobile in the leaf while the calcium tended to migrate to the petiole. 

 Copper sprays increased the turgidity of the cells while the osmotic pressure and molecular 

 concentration of the cell sap (measured by cryoscopic methods) were not materially changed. 

 Leaves treated with polj'sulphides or left untreated contained less protein nitrogen and in- 

 soluble phosphorus compounds than leaves treated with copper sprays, whereas they contained 

 greater quantities of soluble nitrogenous compounds. All spraying materials favored the 

 condensation of sugars into starch and the accumulation of the latter, but Bordeaux mixture 

 was particularly beneficial. In general a parallelism was observed between induced physi- 

 ological variations in the host cell and the anti-cryptogamic effect of the spray, to the extent 

 that the more efficient chemicals were those which also produced the greater stimulation of 

 the host. — A. Bonazzi. 



714. Price, W. A. Bees and their relation to arsenical sprays at blossoming time. Purdue 

 Univ. Agric. Exp. Sta. Bull. 247. 15 p., fig. 1-7. 1920. — Bees were found to work freely on 

 sprayed fruit trees and dead bees were found in abundance. Tests showed that a very small 

 amount of arsenic (less than 0.0000005 gram AsjOj) is a fatal dose for a bee. Bees caged on a 

 tree sprayed when in full bloom with a spray of the formula 1 gallon lime sulphur + 1 pound 

 lead arsenate to 50 gallons of water showed a mortality of 69 per cent. Bees caged on a tree 

 dusted when in full bloom with 85 per cent flowers of sulphur + 15 per cent lead arsenate 

 showed a mortality of 46 per cent. Chemical analyses of the dead bees showed the presence 

 of arsenic. Bees caged on a check tree showed only 19 per cent mortality and no test for 

 arsenic. — Max W . Gardner. 



715. ScHAFFNiT, E. Eiweisserdalkaliverbindungen als Zusatzstoffe fiir Bekampfungs- 

 mittel zur Erhohung des Haftvermogens. [Albumen-alkaline-earth combinations added to 

 spray solutions to increase adhesion.] Zeitschr. Pflanzenkrankh. 31 : 19-22. 1921 . — The author 

 discusses the role of alkaline-earth-metal compounds with certain colloidal substances of the 

 group of albuminoid bodies, such as albumens, globulins, etc. Casein-lime combinations 

 have proved of excellent value in increasing the adhesion of spray substances. — H . T. Gussow. 



716. Smith, G. M., and G. N. Hoffer. Three methods of controlling the root, stalk, and 

 ear rots of com. [Abstract.] Phytopathology 11 : 34. 1921. 



717. Tola AS, A. G. Seed certification makes great progress. Potato Mag. 3'^: 9-11, 25. 

 1921. — The paper includes a tabular summary of rules and conditions regarding potato seed 

 certification in North America in 1920. Plans for yield tests are described. — Donald Folsom. 



718. Valleau, W. D. Selection of disease-free seed and seed treatments as a possible 

 means of control of corn root rot. [Abstract.] Phytopathology 11: 35. 1921. 



719. Weimbr, J. L. Reduction in the strength of the mercuric chlorid solution used for 

 disinfecting sweet potatoes. Jour. Agric. Res. 21: 575-587. 1921. — A bushel of sweet potatoes 

 (Ipomoea) submerged in 135 1. of mercuric chloride, 1 to 1000, for 5 minutes in the manner of 

 common agricultural practice reduces the strength of the solution about 1 per cent. This 

 decrease in strength is attributable to the potatoes themselves, to the dirt and fibrous roots 

 adhering, and to the containers of the potatoes and of the solution. — Washed sweet potatoes 

 and Irish potatoes (Solanum) remove substantially the same amount of mercuric chloride 

 from solution. — A solution may be kept near its original strength bj' adding 11 to 14 gm. of 

 mercuric chloride and water to make up original volume, after treatment of each 10 bushels. — 

 D. Reddick. 



