174 Bacteriologie. — Lichenes. 



was isolated and purified. Under suitable conditions of nutrition, 

 temperature and acidity the bacterium produces, in the laboratory, 

 a gum or slime which is chemically identical with the gum obtained 

 from diseased canes. The gum is therefore not a pathological secre- 

 tion of the plant, but is undoubtedly of microbic origin. For the 

 formation of gum, Saccharose or levulose is necessary; dextrose is 

 not so useful, and the other commonly occurring sugars and carbo- 

 hydrates are useless. Of the saline nutrients, phosphate is essential, 

 and potash can be replaced by calcium or magnesium; sodium salts 

 act as decided poisons to the microbe. The specific characters of the 

 bacterium are described. Smith. 



Britzelmayr, M., Über Cladonia ratigiferina Hoff, und hacillaris 

 Ach. (Beihefte zum bot. Centralblatt, Band. XX. 2. Abteilung, 

 Heft 1, 1906, p. 140—150). 



Verf. beschreibt eine Reihe von Formen einiger stark abändern- 

 den Flechten, wobei, wie es Referenten dünken will, die besten be- 

 schriebenen Formen zu wenig berücksichtigt werden. 



Er gliedert: 1) Cladonia ratigiferina Linn. 



A. Podetia alba, albida, caesia, grisea, fusca, nigricantia: 



sC) vulgaris j h) incrassata , c)scabrosa, d) grandaeva , e) verriiciilosa , 

 f) erytheocroea , g) fuscescens, h) adusta , '\)pninila, \C)flexuosa. 



B. Podetia albido — vel viridulo — straminea aut straminea: 

 a) typica mit f. media und f. minor, b) mutabilis, c) curla. 



2) Cladonia sylvatica Linn.: 



A. Podetia alba, afbida, straminea, pallide fuscescentia aut glau- 

 cescentia: 



a) major, b) sphagnoides , c) rohusta, d) tenuior, e) fuscescens mit 

 f. media und f. minor, f) arbuscula, g) tenuis , h) stramineo—alba, 

 i) hians. 



C. Podetia glauca, caesia, non grisea: 

 a) glauca, h)/issa, c)suberecta, d) nana. 



C. Podetia grisea, sordide grisea, nigrescentia : 

 a) grisea, b) longiuscula , c) pumila , d) nigrescens. 



D. Podetia viridantia: 

 a) viridajis. 



3) Cladonia alpestris Linn. 

 a) alpestris L. , b) campestris. 



4) Cladonia bacillaris Nijl. 



A. Clavata: 



a) vulgatus mit f. tenuis, media und robusta, b) polycephala, 

 c) niacrocephala , d) crispula , e) crassa , f) paschalis, g) microphyllifui , 

 h) longa, i) proboscidea. 



B. Podetia cruciformia: 



a) perithetum Wallr. h) abbreinata , c) abnormis. 



C. elegcnitior Wainio. 



D. scyplioidea : 



a) gracilis, b) radiata , c) prolifera. 



E. fruticulescens Wainio. 



F. lateralis. 



a) rantosa, b) sessilis. 



G. gigantida. 



2i}elatior, h) cornuta, c) irregularis , d) iitcondita. 

 H. corticata. 

 a) glonierosa. 



