236 PATHOLOGY [Bot. Absts. 



cuticle, the acid sap of the cells acting to dissolve some of the copper the same as the germ- 

 tubes of Phytophthora. — The literature dealing with the effects of bordeaux mixture on unin- 

 jured healthy potato plants is reviewed in considerable detail, the conclusion being that the 

 shading due to the mixture is probably the active factor. To test this the author conducted 

 four sets of experiments with the blight resistant Red Star potato, having in each an un- 

 sprayed plot, one sprayed with lime milk, and one with bordeaux. Plots sprayed with lime 

 milk gave the highest yield, that of the bordeaux being next highest in spite of the fact that 

 the latter remained green from two to three weeks longer. The author's results thus sup- 

 port the conclusion that the beneficial effects of bordeaux on healthy plants is to be attrib- 

 uted to the shading it produces during very sunny seasons, while for the same reason the 

 yield is reduced in cloudy seasons. These experiments are to be repeated on a more exten- 

 sive scale in 1919. — H. H. Whetzel. 



1655. Ritzema Bos, J. De gevolgen van een fout bij het snoeien ban laanboomen. [The 

 results of an error in pruning shade trees.] Tijdschr. Plantenz. 24 (Bijblad): 49-51. 1918. — 

 A popular presentation of the injurious results of leaving stubs in pruning, with special 

 reference to attacks of Neclria cinnabarina through such wounds. — H. H. Whetzel. 



1656. Rosen, H. H. A preliminary note on a bacterial disease of foxtail. Science 49: 

 291. 1919. — The disease appeared on foxtail (Setaria glauca) at Fayetteville, Arkansas, 

 from September to November. Leaves, flowering stalks and glumes became spotted and 

 streaked with dark brown areas. The pathogene, a white, rod-shaped bacterium, was iso- 

 lated and grown in pure culture. By spraying and by needle smears, the following plants were 

 infected: wheat, oats, rye, barley, corn and Sudan grass. The organism may be Pseudomonas 

 avenae. — A. H. Chivers. 



1657. Schoevers, T. A. C. Kieuwe ziekten, waarop gelet moet worden. [New diseases, 

 which may become dangerous.] Tijdschr. Plantenz. 25:95-98. 126-128. 1919. — There was 

 observed in different places in Holland in 1918 a hitherto unreported disease of spinach. 

 The symptoms exhibited were: a languishing and yellowing, with poor growth and final death 

 of the plants in spots here and there in the beds. Affected seedlings showed a crumpling of 

 the cotyledons. The tap root of disease plants was constricted for some distance below the 

 crown, with a brownish discoloration of the tissues. Side roots were usually wanting or had 

 taken the place of the tap root but showed the brown constrictions. Growing root tips were 

 wanting. — Microscopic examination showed the contents of the cortical cells of the con- 

 stricted region dead. The walls were brown; those of the vessels also darker than normal. 

 Minute protozoan-like bodies filled many of the cells, especially those of the cortex, but 

 occurred also in the cells of the endodermis, vascular bundles and root hairs. The organism 

 is described in Mededeelingen van de Landbouw-hoogeschool, part 15, page 75. Attempts to 

 reproduce the disease by growing plants in soil from diseased areas failed. The nature of the 

 bodies in the cells of diseased roots has not been determined. — In tomatoes, petunias, asters, 

 wall-flowers and Gilia tricolor there has been reported from Ireland by Pethybridge and Laf- 

 ferty (Scientific Proc. Roy. Dublin Soc. 15: — . 1919) a new disease caused by a heretofore 

 undescribed fungus, Phytophthora cryptogea. While this has not yet been reported from 

 Holland the writer rather expects it may occur there. He reviews the paper of the above au- 

 thors in some detail, especially that dealing with symptoms and soil infestation in order 

 that Dutch growers may acquaint themselves with the disease and be on the lookout for it. — 

 H. H. Whetzel. 



1658. Schoevers, T. A. C. Wat nu in den boomgaard gedaan kan worden ter bestrijding 

 van ziekten en plagen. [What may now be done in the orchard toward combatting diseases and 

 pests.] Tijdschr. Plantenz. 25 (Bijblad): 1-4. 1919. — Timely notes on the more common 

 fungous and insect pests of the orchard that may be combatted to some extent by pruning 

 in the early spring. The diseases discussed are: monilia-rot, scab, cankers and witches' 

 brooms. — //. H. Whetzel. 



