106 PATHOLOGY [BoT. Absts., Vol. X, 



679. Gardner, Max W., and James B. Kendrick. Bacterial spot of tomato. [Abstract.] 

 Phytopathology 11: 55. 1921. 



680. Gerretsen, F. C. Die Bakterien der Coli-Asrogenes-Gruppe als Erreger von Pflan- 

 zenkrankheiten. [Bacteria of the Coli-aerogenes group as the cause of plant diseases.] Zeit- 

 schr. PHanzenkraiikh. 30: 223-227. 1920. — Investigations of Wakker's disease of hyacinths 

 revealed that, besides Bacterium hyacinthi, in some cases another specific bacterium occurred. 

 The latter was grown in pure culture and used in inoculating a number of bulbs of Hyacinthus 

 orientalis. After 40-60 days, in nearly all cases, 1 or more bulb scales had become infected. 

 This bacterium was shown to be the cause of a disease in H. orientalis and Galtonia candicans, 

 when introduced into the tissues through a wound. The bacterium was studied according 

 to the schedule of the Society of American Bacteriologists, receiving the classification number 

 222.111.301. The author regards the bacterium as of the colon bacillus group which, however, 

 has lost its power of gas production in passing through the plant. — H. T. Giissow. 



681. GtJssow, H. T. Correspondence ecrite. [A letter to Et. Foex on rose canker.] Bull, 

 Soc. Path. Veg. France 8: 30. 1921. — The writer states that Sorauer, Wulff, Foex, and himself 

 are all wrong in attributing the rose canker of Europe and Canada to frost or Coniothyrium. 

 He believes after further study that it is due to Bacterium tumefaciens. — C. L. Shear. 



682. Himmelbaur, W. Heterosporium gracile (Wallroth) Saccardo auf Irisblattern. 

 [Hetersporium gracile (Wallroth) Saccardo on Iris leaves.] Zeitschr. Landw. Versuchsw. 

 Deutsch Osterreich 23: 131-141. 7 fig. 1920. — A disease of iris leaves due to Heterosporium 

 gracile is described. A description of the fungus, its life history, and mode of entrance into 

 the host are given. The fungus is considered as only weakly parasitic, and is able to cause 

 serious injury only on plants so closely placed as to prevent proper air circulation, and then 

 only in wet seasons. Microchemical reactions of the diseased parts and of the fungous my- 

 celium are given. The placing of plants far enough apart to allow proper circulation of air is 

 recommended. — John W. Roberts. 



683. Janchen, Erwin. Der Kartoffelschorf. [Potato scab.] Oesterreich. Zeitschr. 

 Kartoffelbau V: 11-12; l"*: 14. 1921. — Three kinds of potato scab from the standpoint of symp- 

 toms are distinguished, — shallow scab, deep scab, and knobby scab; etiologically there are 

 Actinomyces and Spongospora scabs. Following Wollenweber the different manifestations 

 of Actinomyces scab are attributed to different species: Thus Actinomyces incanescens Wr. 

 causes deep scab; A. tricolor Wr., shallow scab; A. intermedius (Kriig.) Wr. and A. nigrificans 

 (Kriig.) Wr. produce shallow scab on potatoes and girdle scab of beets; A. serugineus Wr, 

 causes knobby scab of potatoes; A. xanthostroma Wr. and A. albus (R. D.) Gasp, with its 

 varieties ochroleucus (Neuk.) Wr. and cretaceus (Kriig.) Wr. produce girdle scab on beets, 

 but may also attack potatoes. Scab of other root vegetables is caused by one or more of the 

 species named. — Typically, knobby scab results from attack of Spongospora subterranea; 

 the disease is also known as powdery or spongy scab. Spongospora and Plasmodiophora are 

 referrred to the Chytridiales. The relation of soil type, moisture, and reaction to the develop- 

 ment of different kinds of scab is discussed. Where potato fields are generally scab-infested 

 the use of resistant varieties is recommended as the best means of control. Some varieties 

 are both immune to wart and resistant to scab. — F. Weiss. 



684. Janchen, Erwin. Die Diirrfleckenkrankheit der Kartoffeln. [The dry-leaf-spot 

 of potatoes.] Oesterreich. Zeitschr. Kartoffelbau V: 24. 1921. — Distinctive characteristics 

 of leaf blight of potatoes caused by Macrosporium solani and control measures for same are 

 given ; this disease is becoming of economic importance throughout central Europe. — F. Weiss. 



685. Johnson, A. G., and R. W. Leukel. The nematode disease of cereals. [Abstract.] 

 Phytopathology 11:41. 1921 . 



686. McKinney, H. H. The so-called take-all disease of wheat. [Abstract.] Phyto- 

 pathology 11: 37. 1921. 



