530 



SYSTEMATIC HISTORY OF THE INFUSOfilA. 



(Bacterium), a single vibratory filament is present. In this same genus the 

 individuals are strung more tightly together, so that the filiform cluster, not 

 being able to exert the writhing movement seen in the true Vibrionia, moves 

 rigidly in a direct course. In Sinrillimi the articulations or lines of imperfect 

 fission are oblique ; hence increase in length by division engenders a spiral 

 chain. 



The animals of this family, says Dujardin, "are the first Infusoria which 

 present themselves in all infusions, and those which from their extreme small- 

 ness and the imperfection of our means of observation must be considered the 

 most simple ; .... and it is only their more or less active movements which 

 lead to their being regarded as animals. I have been sometimes induced to 

 believe that a flagelliform filament, analogous to that of Monads, or rather a 

 spiral undulating one, exists, and that this is the cause of the peculiar mode 

 of locomotion. Is the Bacterium tiiloculare, described by Ehrenberg as having 

 a proboscis, a true Yibrio ? 



*' All that can be with certainty predicted respecting their organization is 

 that they are contractile, and propagate by spontaneous fission, often imperfect, 

 and hence giving rise to chains of greater or less length." 



As stated in our general history of the family (p. 184), the present tendency 

 among natiu^alists is to refer Vibrionia to the vegetable kingdom. Cohn 

 assigns them a place in the family Mycophycese among the microscopic aquatic 

 Eungi. Perty retains them in his group Phytozoida, expressing at the same 

 time his conviction that they are of a vegetable nature. Indeed the only 

 reasons advanced by Ehrenberg in support of the animality of Vibrionia are, 

 that they are actively, and, to his apprehension, voluntarily moving beings, 

 and multiply by self- division, — reasons which, in the present state of know- 

 ledge, must be held worthless, A re- examination of aU the enumerated 

 species, as Cohn remarks, is imperatively necessary before we can come to 

 any safe conclusions relative to the true structure and affinities of the 

 Vibrionia ; and this same able observer has himself set the example by con- 

 ducting such an examination of one species as to clearly indicate its physio- 

 logical characters and its relation to PalmeUa and Tetraspora among the 

 Algae, and more particularly to Sjjhcerotilus among Mycophyceaj. 



The Vibrionia are developed with extreme rapidity in aU liquids containing 

 changed or decomposed organic substances, in animal fluids — the saKva, serum, 

 mine, &c. When coloming matter has been mingled with the water, its 

 imbibition by the corpuscles has never been observed. 



This family is distributed by Ehrenberg as follows : — 



Articulated threads (clusters) f Inflexible Bacterium. 



straight, the transverse divisions i 



being rectangular [ Flexible, Hke a snake Vibrio. 



Articulated threads spirally twisted r^lexible Spirochajta. 



(like a bell-spring or cork-screw), / .,, r j- n i 



%J:r'''' clivisions bein^g ^xtded^p^tiS^ '^^^^ 



^^l^^l^" Unflexible. ' ^ 



I with a compressed I g i^odiscus. 

 l^ spiral lorm J ^ 



On this subdivision of the family Vibrionia, Cohn (Entiu. p. 117) has ex- 

 pressed himself very strongly. He says, ^' An inextricable confusion prevails 

 when specific characteristics are attempted : we have the observations, good 

 and bad, of various authors, weak and strong amplification of the objects, 

 young and old conditions commingled without any critical endeavour to 

 distinguish between them." Eeehng that there is no sufficient basis for it, 

 Cohn does not attemjit a classification of the Vibrionia. The Monas Lineola 



