232 Infusorial Circuit of Generations. 



roughish, but very hyaline, cucumber-shaped form ; each " cucum- 

 ber " at first crowned with a true vorticellan pitcher-mouth, mostly, 

 however, closed and rounded over, occasionally gaping or as it were 

 yawning spasmodically, at intervals only, and which finally " shut 

 up " for good. The little glassy knobs — like so many trunk-nails — 

 that covered the surface, grow into soft jerking-bristles ;* the mouth 

 into the well-known mustachioed slit of barbiform cilia ; and the 

 wan, limpid, empty and now entirely flattened, ligulate or sandal- 

 shaped body tears loose as a young fluttering, pallescent Oxytricha 

 (Pelionella), or so-called " hackle-animalcule " ; darting by the 

 jerks of its stifiish marginal bristles, and by the constant " plying " 

 of the long-barbed, ciliate sht efiecting its slower progress. It 

 never revolves, but often crawls; both in contradistinction to the 

 fleeced, revolving, and vacuole-propelled " Paramecium " form. 



This is probably the " short-line " development of Oxytricha, 

 directly from the germinal clouds or the parasite of Chlamydococcus 

 through Vorticella. I have no good figures to refer to, since even 

 the detailed ones of Ehrenberg, in ' Trans. Berhn Acad. Sc.,' 1833, 

 tab. iii., figs, ii., iii., and iv., which belong here (as well as 

 tab. xxiv. and xxv. of A. Pritchard's ' Hist. Inf.,' 1861), are too 

 inaccurate to serve as a guide, or to be readily identifiable even by 

 those acquainted with the real natural object-material itself. 



At first the bristles of the (tongue-shaped, flat, and elongate- 

 elliptical) Oxytricha are fluttering and tremulous ; but as it feeds 

 and rapidly increases in bulk, all the well-known characters of the 

 complete "Oxytricha," its stiffish darting-bristles, its grumose, 

 obscured body, irregularly replete with granular yolks, and very 

 frequently cross - dividing, become typified. When thus cross- 

 divided (a process well known and abundantly figured) the front 

 })art alone retains the barbed mouth, which, from the apex, switches 

 down like a mustachio on a longitudinal slit about a quarter of 

 the whole length. The blunt rear-part, on the contrary, separates 

 with an incurrent angle which soon contracts into a new mouth, 

 whereby the rear animal takes a blunter shape (like the cotyledon 

 of an almond, the flat side downward). 



The Oxytricha is by no means, however, to be considered as 

 an adult form, since it is never seen to exhibit a continuity as of a 

 membrane, or of internal ducts or viscera. Neither is it seen to 

 " copulate " or adhere lengthwise, or in any other fashion to one 

 another except in the process of self-division. Nor does it readily 

 divide by longitudinal fission in this state. I have seen this only 



* In their onward development these softish bristlca arc indurated into " styles " 

 (of specialists). The attentive reader will observe thsit on such alteiations of growth 

 alone a great many colloiding false genera and species have been formed. Sup. gut. 

 Wc have naturally to reject all, of which the imdo of development remains unknown, 

 as indicating a false stand-point. 



