27'6 F. iEPFRilY BELi. 



Tribe II. — Nematogenae Rab. 



Cells arranged in rows. 



a. — Cell-threads free, or in a felted mass : 



I. — Threads cylindrical, colourless, indistinctly jointed. 



Very fine and short .... Bacillus, Cohn. 



Very fine and long Leptothrix, Kg. em. 



Thicker and long Beggiatoa, Trev. 



II.— Thread cylindrical, containing phycochrom, distinctly jointed : 



Reproductive-cells unknown . { Sw? Boi"*et al. 

 HI. — Threads cylindrical, jointed, forming Gonidia : 



Colourless Crenothrix, Cohn. 



With phycochrom Cliamaesiphon, et al. 



IV. — Threads screw- shaped : 



1. Without Phycochrom. 



Short, slightly undulating . . Vibrio, Ehr. em. 



Short, spiral, stiff Spirillum, Ehr. 



Long, spiral, flexible .... Spirochete, Ehr. 

 2. With Phycochrom. 



Long, spiral, flexible .... Spirulim, Link. 

 V. — Threads form a rosary-chain : 



Without phycochrom .... Streptococcus, Billr. 



With phycochrom .... H'^^^'^^^. Borg. 



^ ^ \Spermosira, Kg. et al. 



'"'"tht'point^'".^"^'!'"'.^'"''?"^. ^^]^I''sti90thrir,\t al. 

 /3.-~Threads united into gelatinous families by their intercellular substance : 

 I. — Cylindrical and colourless . . . Myconostoc, Cohn. 



„,-0,lindrical. with phjcochron, { f^S-^Kg. et al. 

 III. — Forming rosary-chains . . . Nostoc-HormosipJioii, et al. 

 lv.-Whip.like.grow«gattheirp„mt {SSi^^'lg.'et al. 

 y. — Threads exhibit spurious branching : 



i.-Cjlindrical and colourless . . {S^te?'''"' 

 U.-C,lindrieal, «th phjeoehrom } g^^il^g. et al. 

 n,.-For.i„grosar,.ebaias . . {^£i^i^g„„„. 

 .v.-Wbip.like,growi„gattheir point ] ftjSSf^'/lV, 



In the paper which concludes this 3rd Heft, Dr. Edward 

 Eidatti, who has been working under Cohn's direction in the 

 University of Breslau, takes up the interesting questions of 

 the influence of different temperatures, and of drying on Bac- 

 terium termo, Duj., with special regard to its development. 

 Cohn himself had worked at the subject, and in his previous 

 paper (in Heft II) had found the maximum mortal tem- 

 perature (the experiment lasting for an hour) to be about 

 60° to 62° C. But both Cohn's points and that of Schroter 



