Fungi, Bacteria und Pathologie. — Bryophyten. 277 



The author describes the phenomenon of specialization of parasitism 

 which has been found to occur in certain groups of fungi. This 

 specialization has led to the evolution, vvithin a morphological species, 

 of several „bioiogic forms", which are morphologically identical, but 

 which differ physiologically or biologically in possessing distinctive and 

 sharply defined infection-powers. 



A preliminary account is then given of the results obtained by him 

 in recent inoculation experiments with several species of Erysiphaceae. 

 The facts obtained show: 1) The high degree of specialization reached 

 in the adaptive parasitism of Erysiphe Graminis to the various host- 

 species within the genus Biomus; 2) The existence of „bioiogic 

 forms", of host plants, i. e. forms of a host species, which are 

 morphologically identical, but which differ constitutionally, so as to be 

 immune or susceptible to the same fungus ; and 3) the existence of 

 certain host species, which serve as „bridging species", in affording a 

 passage for certain forms of the fungus to species of host plants which 

 they are unable directly to infect. The paper is illustrated by diagrams. 

 Füll details of the experiments carried out will appear in the Annales 

 mycologici. Vol. II. June 1901. A. D. Cotton. 



TOWNSEND, CO., A Soft Rot of the Calla Lily. (U. S. 

 Department of Agriculture. Bureau of Plant Industry Bull. 60. 

 Jim. 30, 1904. 44 pp. 9 pl. 7 fig.) 



This bulletin contains a description in detail of the soft rot of the 

 Calla Lily. the morphological and physiological characters of the 

 organism causing it, viz. — Bacillus aroideae n. sp. Remedies for the 

 prevention of the disease are suggested. 



Bacillus aroideae is a short rod bearing peritrichiate flagella. It 

 spreads through the intercellular spores of the tissues oi the host and 

 dissolves the layers that connect the cells, causing the affected tissue 

 to break down into a slimy mass. It is able to attack a large number 

 of kinds of raw vegetables. It does not attack tree fruits readily. It 

 grows readily on beef agar. It forms radiating colonies under more 

 favorable temperatures, and round ones under less favorable. It liquefies 

 gelatin, coagulates milk, first reddens, then blanches blue litmus milk. 

 It does not produce gas and is aerobic. I causes a soft, dark colored 

 rot not only of the calla lily but also of the carrot, potato, turnip, 

 radish, cabbage, and cauliflower. It rots the green fruits of the tomato, 

 egg-plant and cucumber. Hedgcock. 



Loeske, LEOPOLD, Erster Nachtrag zur „Moosflora des 



Harzes". (Festschrift zu P. Ascherson's siebzigstem 



Geburtstage, p. 280— 295. Berlin [Gebr. Borntraeger] 1904.) 



Neu für ganz Deutschland: Barbula obtusula Lindbg. (in der 

 „Moosflora des Harzes" des Verf. 's als Barbula revoluta Brid. var. 

 mucronata Lske. bezeichnet). — Neu für den ganzen Harz: Riccia 

 intumescens Underw., Sarcoscyphus ustulatus Kiaer, Lophozia longidens 

 (Ldbg.) Evans, Sphaojiam crassicladum Wstf., Sph. Warnstorfii Russ., 

 Ephemerum Zichackeanum Wstf., Myurella julacea, Plagiolhecium late- 

 bricola Br. eur., Drepanocladus Wilsoni (Schpr.). — Neu für den Süd- 

 harz: Dicranodontium longirostre mit Campylopus flexuosus, Barbula 

 gracilis, Plagiopus Oederi, Platygyrium repens, Amblystegium Sprucei, 

 Hypnum scorpioides. — Neu für den Unter harz: Cephalozia Lam- 

 mersiana Schffn., Sphagnum fimbriatum Wils., Sph. Girgensohnii, Sph. 

 subsecundum Spr. mit var. decipiens Wstf., Sph. inundatum Wstf., Sph. 

 contortum Lpr., Russowü Wstf., parvifolium Wstf., Ditrichum vaginans 

 c. fr. — Zu streichen aus der Liste der Harzmoose sind: 

 Jungermannia Wallrothiana Nees (gehört nach Prof. V. Schiffner 

 theils zu Lophozia badensis, theils zu L. Mülleri var. pumila [NeesJ 



