72 Bacteriologie. — Pteridophyten. 



Jordan, E. O., Variation in Bacteria. (Proceed. nat. Ac. Sc. 

 I. p. 160-164, 1915.) 



The author has experimented with Bacterium coli and says: The 

 differentiation of this organism into species is commonly made on 

 the basis of the power to ferment Saccharose and most of the recent 

 classifications of B. coli groups Start with this, as a fundamental 

 distinction. In the great majority of strains of this organism that 

 have been tested by various observers Saccharose fermentation is 

 correlated with raffinose fermentation. Saccharose-fermenting Strep- 

 tococci on the other hand are often devoid of power to ferment raf- 

 finose. The acquisition of this new character by an originally non- 

 saccharose-fermenting strain of B. coli has thus far developed only 

 once and then on sodium Chloride medium. Cultures of the parent 

 organism grown in Saccharose broth for a series of generations as 

 yet show no gas production or acid production. This particular 

 change therefore seems to be due to the intra-cellular or molecular 

 changes brought about by non-specific influences and not to a direct 

 adaptation to particular environmental conditions. 



Matouschek (Wien), 



Walcott, C. D., Discovery of Algonkian Bacteria, (Proceed. 

 nat. Ac. Sc. I. p, 256—257. 1 Fig, 1915.) 



The bacteria are in association with the algal deposits on the 

 Newland limestone, a formation of the Beltian series of Algonkian 

 rocks in Central-Montana. The bacteria consist of individual 

 cells and apparent chains of cells which correspond in their physical 

 appearance with the cells of Micrococci. For the purpose of compa- 

 rison an illustration is here given of a group of recent forms as 

 shown in the „Encyclopedia ßritannica" and of the form shown in 

 the cells in the thin sections cut from the fossil alga of the named 

 locality. Matouschek (Wien). 



Davie , R. C, The Development of the SorusandSporan- 

 gium of Peranema cyatheoides D, Don. (Annais Botany. XXX. 

 NO 117. p, 101—110. 3 PI. and 2 figs. in the text, January 1916.) 



In Peranema cyatheoides the indusium forms a cup round the 

 receptacle, one side of this cup being curved over the top of the 

 receptacle and a small portion of the other side being missing. As 

 the sorus matures marked elongation of the receptacle occurs re- 

 sulting in the formation of a soral stalk, the peripheral part of the 

 latter being continuous with the indusium. Every sorus is produced 

 at the end of a vein or vascular Strand; the latter entering and 

 spreading out in a fan-like manner in the receptacle. The sorus is 

 at first of the gradate type, but before maturity it becomes mixed. 



As regards soral and indusial characters P. cyatheoides is inter- 

 mediate between the Cyatheaceae and Polypodiaceae; it resembles 

 the latter group in its distinctly Nephrodioid vascular System, its 

 mixed sorus and „Aspidioid" spores; on the other hand the Cya- 

 theoid characters preponderate as is shown by the development of 

 the indusium and sporangium as well as by the gradate receptacle 

 earlier sporangial sequence and number of spores. The prothallus 

 bears glandulär hairs and the lid-cell of the antheridium is nearly 

 alwaj^s undivided. Isabel Browne (London). 



