PSEUDODICHOTOMY. 19 



Long screw (Langschraube) = spiral form (h) : all screw forms possess 

 either steep or flat turns. 



tfjihidfc fonnx (Spindelform) (t). 



Oval rods (Ovalstabchen) (k) are differentiated from the spindle form 

 by less tapering ends, from the oval form by their greater length = 

 2-4 X the width. 



Clubbed form (Keulenform) (I). 



Growth Groupings. 



Diplococcus (Doppelkugel) (m) with barely perceptible separation: 

 Biscuit form (n). 



Streptococcus brevis (Kugelreihe) (o) up to 8 cocci ; with barely per- 

 ceptible separation : Torula form (p). 



Streptococcus longus (Kugelfaden)(g), or, if bent, Rosary form (Rosen- 

 kranzform) (s] ; with barely perceptible separation : Torula threads (r). 



Staphylococcus (Traubenform) (t). Diplobacillus (Doppelstabchen) 

 '(M). Jointed threads (giederfaden) (v). 



Tetrad (Tetradenform) (w): plane grouping of 4, 8, 16, etc., cells. 



Sarcina (Wiirfelform) (a;), cubical form : solid grouping of 8, 32, 

 etc , cells. 



Branching, i. e., springing up of a side bud, was until 

 recently unknown in connection with bacteria, and it is, 

 at all events, rare. Besides in others, it is well established 

 in the so-called tubercle and diphtheria bacilli as a frequent 

 appearance, and thus it is demonstrated that here forms 

 occur which do not strictly belong to bacteria. 



Exceptionally, true branching appears to occur in other 

 varieties. Heim mentions it in Bact. fluorescens. Vin- 

 cenzi (C. B. xiv, 149) appears to have observed the same 

 in tetanus, but in spite of special care, we have made no 

 similar observations. 



Often pseudodichotomy is confused with branching and 

 dichotomy. According to Babes (Z. H. xx, 412), it occurs 

 not infrequently in the most typical bacteria, and consists 

 in this, that either the lower member of a thread grows past 

 the side of the upper member, or that, in a row of cocci, 

 the division of a coccus parallel to the direction of the 

 string suddenly creates the beginning of a second thread. 

 Stolz (C. B. xxiv, 337) has recently studied exhaustively 



1 Some authors falsely designate this true branching as true dichot- 

 omy, but true dichotomy means, according to botanical usage, only 

 the di vision of the growing ends of threads into two equal twigs, and 

 it is not certainly known to occur in bacteria. 



