FUBBUABY, 1920] PATHOLOGY .">'.> 



overcome the trouble, and still grow the desired White Burley, the authors present results of 

 selecting for disease resistance. Individuals winch remained healthy on "sick" soil were 

 selected, propagated and tested over a period of several years. Under varied COndil ions these 

 strains have maintained their original degree of resistance. The resistant strain is practically 

 equal to the ordinary Hurley in quality (color and texture) of the cured product. It also 

 brings as good price on the warehouse floor as the ordinary Hurley. For "sick" soils, the 

 resistant Burley strains are advised for White Burley districts; for "healthy" soils the 

 ordinary Burley may be preferred. [See Bot. Absts. 3, Entry 43.] — L. Ii. Hosier. 



404. Johnston, J. II., and Stephen C. Bruner. A Phyllachora disease of the royal palm. 

 Mycologia 10:43-44. PL 2. 1918. 



405. Lathrop, F. H. Leaf-hoppers injurious to apple trees. New York Agric. Exp. Sta. 

 [Geneva] Bull. 451 : 185-200. PL /-/,, fig. 1-2. 1918— Consists, chiefly, of a discussion of the 

 distinguishing characteristics, seasonal activities, and life stages of three species of leaf- 

 hoppers which attack the cultivated apple [Malus sylvestris], viz., Empoasca Mali LeBaron, 

 E. unicolor Gill., and Empoa rosae L. On pages 195-198 there is an account of some experi- 

 ments the object of which was to ascertain the rMe of these insects in the transmission of 

 the fire blight disease caused by Bacillus atnylovorus. The insects were first permitted to feed 

 for a time on blighted apple shoots after which they were transferred to cages containing 

 healthy shoots. Positive results were obtained with E. Mali; but the other two species gave 

 negative results, except in one doubtful instance. The behavior of the insects indicated 

 that the diseased tissue was distasteful and injurious to them. — F. C. Stewart. 



406. Lee, H. A. Copper stearate. Ann. Rept. Agric. and Hortic. Res. Sta. Univ. Bristol 

 1917:39—12. [1918.] — If copper sulfate solution is added to soap solution an opaque light 

 blue precipitate appears, the individual particles of which measure 2-3/*. Both solutions 

 must be dilute (1 per cent) and the soap must be in excess. If much more than 20 cc. of 

 copper sulfate solution is added to 100 cc. of soap solution a sticky mass is formed. The 

 chemistry of the mixture is discussed. It wets resistant surfaces and combined with 2 per 

 cent paraffin emulsion will wet such surfaces as mildew spots. Once dried on foliage it 

 resists wetting completely. Its fungicidal properties have not been determined. — D. Reddick. 



407. MacMillan, H. G. Fusarium-blight of potatoes under irrigation. Jour. Agric. 

 Res. 16:279-303. PL 37-41. 1919.— Report of the investigations made in the Greeley, 

 Colorado district during the years 1915, 1916, 1917 of the disease commonly known as "potato- 

 wilt," "Fusarium-wilt," etc. The term "Fusarium-blight" is suggested as being more 

 applicable to all stages of the disease. Fusarium oxysporum was found to bring about all 

 phases of the disease; other species of Fusarium were found to bring about similar phenomena. 

 Remarkable symptoms of the disease noted are, (a) wilting and dying of a single leaf while the 

 remainder of the plant remains healthy, (b) evidence of the disease "when the first leaves 

 appear," (c) passing of a plant from health to complete collapse within two days, and, (d) 

 rolling of the leaves without the usual wilting. The soil, not the seed, is the principle source 

 of the inoculum. Seed pieces furnish an important avenue of attack, injured surfaces being 

 much more vulnerable than uninjured ones. Certain Rural varieties were found remark- 

 ably susceptible and certain Pearl varieties remarkably resistant to the disease. — Selection 

 for resistance, superior cultural practice, and the use of whole seed free from wounds are 

 suggested as control measures. — Charles R. Stevenson. 



408. Martin, Walter. The physical factors influencing infection. Ann. Surg. Phila- 

 delphia, 68:436-445. 1918. — A general discussion of wound infection, placing emphasis 

 upon the importance of pressure at the focus of infection, the presence of foreign bodies, the 

 effect of devitalized and necrotic tissues, and the presence of dead spaces in the wound. 

 [Abst. by G. H. S[mith] in Abst. Bact. 2, Entry 2150.] 



