Pfianzenkrankheiten. — ßryophyten. 259 



investigation into the nature and cause of the disease. Lewis has 

 studied the disease into detail; beginning with the study of a bac- 

 terial disease of Erodiian texanntn, a wildgrowing plant, abundantly 

 occurring in Texas, he stated by inoculation-experiments the iden- 

 tity of two diseases, and their causing organism. The organism, 

 isolated from Erodimn and that from the cultivated varieties of 

 Pelargoniuin are one and the same. No cultivated varieties have 

 been discovered that are immune. The organism does not seem 

 capable of affecting other species of plants. Inoculations were made 

 into young cabbage plants, lettuce, beans and nasturtiums, but all 

 these failed. 



The author describes in this paper the appearance of the leaf 

 spot, the Isolation method used, the inoculation experiments, the 

 cultural characteristics of the organism, its growing on agar plates, 

 on peptone agar, in glucose agar stab cultures, in lactose agar stab 

 cultures, in steamed potato cylinders, in steamed cocoanut, in 

 litmus milk, in sterile milk, in Dunham's Solution, in peptone 

 bouillon, in Dunham's Solution with met34ene blue, in bouillon 

 with sodium chlorid, in bouillon over Chloroform, in decoction of 

 Erodhan\ea.\eSy in Erodüema.ga.r, in decoction of geraniumleaves, 

 in nitratebouillon , in Fermis' Solution, in Cohn's Solution, in 

 Uschi nsky's Solution, in peptone gelatin stab culture, in lactose 

 litmus agar, in steamed carrot cylinders and on steamed white 

 turnips; other characteristics as production of indol, of bydrogen- 

 sulphid, of ammonia, nitratereduction, litmusreduction, reduction 

 of methylene blue, the thermal death point, are described. The 

 organism will not grow in an atmosphere devoid of oxygene, 

 but will retain its vitality in an atmosphere of nitrogen. Then fol- 

 lows its relation to moisture, its growth in fermentation tubes, 

 its sensitiveness to acids and alkalies, the morpholog}'^ of the orga- 

 nism, the natural infection and control, the technical description 

 of the organism. 



The organism is called Bacterium {Pseudomonas) Erodii I. M. 

 Lewis nov. spec; the generic name Bacterium being in accord with 

 the usage favored by E. F. Smith; by Migula's System the name 

 becomes Pseudomonas Erodii. According to the numerical designa- 

 tion of the Society of American Bacteriologists the ^roup number 

 of B. Erodii is 211.2222122. M. J. Sirks (Haarlem). 



Loeske, L., Scapania paludicola Lsk. et C. Müll. Ein Beitrag 

 zur Frage der Parallel formen bei den Moosen. (Magyar 

 bot. lapok. XIII. 10/12. p. 298—302. Budapest 1914. Deutsch mit 

 Ungar. Resume.) 



Der Verf. beobachtete, dass aus zwei verschiedenen Arten durch 

 gleiche Lebensbedingungen Parallelformen erzeugt werden. Diese 

 zwei Arten sind Scapania undulata und Scapania irrigua, die dies- 

 bezüglichen Parallelformen sind var. pahidosa C. Müll, und var. 

 nova paludicola L. Loeske. Diese zwei Formen sind insofern gut zu 

 unterscheiden, als Sc. undulata stets gleichmässig verdickte Zell- 

 wände des Blattes besitzt, während Sc. irrigua immer dreieckige 

 Zeilverdickungen aufweist. Diese angegebenen Unterschiede im 

 Zellnetze gehören zu den erblich fixierten, phyletischen. Die beiden 

 Parallelformen zeigen denselben schlaffen Wuchs, die gleiche bleich- 

 grüne Farbe, die kurze auffällige kreisbogenförmig gekrümmte 

 Kommissur, und leben in hochgelegenen Sümpfen. — Wie vermögen 



