260 F. JEFFREY BELL. 



Berlin, in 1874.^ I shall try to give in the following pages 

 an account of these two new papers, but must refer all who are 

 really interested in the matter from whatever point of view, 

 philosophical, botanical, or pathological, to the originals them- 

 selves, assuring them that difFuseness will not be found to 

 be a characteristic of this memoir. Notwithstanding Bill- 

 roth's work, Cohn holds firmly to his original position, 

 that the Bacteria should be arranged in genera and species, 

 and not united into a single polymorphous species — 

 Coccobacteria septica (Billroth), as has happened to all the 

 forms described by him, with the exception of Spirillum and 

 Spirochcete, under the hands of Billroth. Readers of this 

 Journal will remember that Mr. Lankester speaks of B. 

 rubescens as a Protean species. Against such a view Cohn 

 argues that the changes of form are not fully proved, nor 

 does he think that such a way of looking at these organisms 

 will be as conducive to progress in our knowledge as his 

 more objective method. With so much byway of introduc- 

 tion we will proceed to the consideration of the various 

 forms which Cohn examines, one by one ; it will I think 

 conduce to clearness, if we follow his example. 



1. The first examined is the Ascococcus, studied by Bill- 

 roth. In the careful observation of the Bacteria-films found 

 in water, containing muscle in a state of decomposition, or 

 on hydrocele, and such like fluids, Billroth noticed a certain 

 grey or greenish-grey organism, rounded in contour, of a 

 knobbed or cylindrical form ; the scum which they produce 

 may attain 0"5 mm. in thickness, and forms, on account of its 

 circumscribed position in jars, and such vessels, distinct folds ; 

 it finally sinks to the bottom of the vessel as a flocculent preci- 

 pitate. These folds are caused by " a peculiar vegetative 

 form of the coccos,'' which Billroth calls palmelloid. If em- 

 bedded in "coccoglia" Ascococcus forms spheres or cylinders 

 of Micrococcus, united into colonies, and held together by a 

 remarkably fine glia ; around such a scum no membrane has 

 ever been observed, notwithstanding its definite outline ; 

 but the presence of it is to be considered as probable ; and 

 it is, indeed, remarkably thick in fluids containing beef, with 

 sugar. 



The history of this form is, according to Billroth, of the 

 following character : several large cells form, by transverse 

 division, long, cylindrical, and spiral tubes, in which 

 appear chains of cocci by longitudinal division, and branch- 

 ing ; these repeated branchings produce very small (micro) 



* • Untersuchungen iiber die Vegetationsform von Coccobacteria sep- 

 tica,' &c. 



