1'56 NOIES AND MEMORANDA. 



(third series), vol. xvii, p. 81. ^Atmospheric Bacteria,' by 

 G. r. Dowdesuell, vol. xviii^ p. 88. 'Life-History of Bacillus 

 Anthracis, by Dr. Cossar Ewart, vol. xviii, p. 161. ' The 

 Nature of Fermentation,' by Prof. Lister, vol. xviii, p. 177. 



During the present year an important memoir by the eminent 

 botanist, Cienkowski, has been published in vol. xxv of the 

 ' Memoirs of the Imp. Acad, of Sciences of St. Petersburg,' 

 entitled ' Zur Morphologic der Bacterien.' The Memoir is illus- 

 trated by two ])lates. Cienkowski holds — (1) that just as a 

 Pahnella-condition develops from diverse chlorophyll-green Algro 

 so do Zoogloea-forms arise from several colourless filamentous 

 Algae, {t) Among such generators of Zoogloia are Crenothrix, 

 Le]}iotlinx, and Cladoihrlx dichoioma. From the last-named 

 Alga, in all probability, arise the commonest Zooglcca formations ; 

 those, namely, oi Bacterium iermo and lineola. (3) The Bacteria 

 are transformed by repeated sub-division into Micrococcus ; the 

 latter also arises directly from Leptothrix-hke filaments. (4) 3Ii- 

 crococcus, Bacterium, Tor?(la-fovms, Bacteria-c\\?iins, are not 

 generically different, since they often occur together in the same 

 mass of Zoogloea, which can be proved to have been developed 

 from a colourless Alga, and from which they can be freed and 

 brought into the motile phase. 



Cienkowski's views agree, therefore, to some extent, with 

 those of Hofmann, Liiders, and Billroth, and are diametri- 

 cally opposed to those of Cohn, whose services in this field of 

 research he nevertheless admits are of the highest value. 

 Hofmann, in 'Bot. Zeitiing,^ 1869, p. 253, had, it appears, 

 observed the development of Micrococcus from filamentous 

 forms. Cienkowski is apparently unacquainted with my observa- 

 tions on Bacterium ruhescens, by which the connection of fila- 

 mentous forms with a variety of other forms (biscuit-shaped, 

 spherical, rod-like, aggregated as Zoogloea, or in the form of net- 

 works or of pavements) is demonstrated. 



In the * Proceedings of the Eoyal Society,' No. 188, 1878, 

 Ewart and Geddes describe and figure the various forms present 

 in a growth of a brownish tint which they observed in a tank at 

 University College, London. 



I have no doubt from their description and from observation 

 of the same growth that the organism present was identical with 

 my Bacterium, ruhescens. During the phase in which they ob- 

 served it the production of Sj)irittu?n4orms was exceedingly 

 active. The Sj)iritlum-iorm. observed by Ewart and Geddes and 

 the filaments related to it appear to be identical with those 

 described and figured by Wanning, ' Observations sur quelques 

 Bacteries qui sc rcncontrent sur Ics cotes du Danemark.' Socii'te 

 d'llist. Nat. de Coponhaguo, 1875. Professor (iiard, of l^ille, has 



