566 



SYSTEilATIC HISTORY OF THE rN^FUSORIA. 



portion of the eontaiued Acineta-hody 

 extends beyond the lips like a tongue. 

 This process contains from foiu* to five 

 contractile spaces, variable both in posi- 

 tion and size, as M-ell as changeable in 

 figure, from a circular to a dumb-bell 

 shape. The rounded anterior angles of 

 the proicess support numerous radiating 

 tubular tentacles, neither capitate nor 

 tapering, but retractile and capable of 

 being collected together in cylindrical 

 bundles. The tentacles may be retracted 

 within the lips of the capsular opening ; 

 and when this happens, the anterior mar- 

 gin of the Acineta has a trilobate cha- 

 racter ; and veiy fr'equently a transverse 

 fold makes its appearance behind the 

 middle of the body, and might easily be 

 mistaken for an indication of commenc- 

 ing transverse fission. Sometimes two 

 such folds are displayed. Maximum 

 length of capsule 1-14'", width across 

 the anterior labiate extremity 1-19'" ; 

 length of pedicle 1-125'". 



In figure and other respects this Aci- 

 neta, remarks Stein, difiers so mate- 

 rially from those of other Acinetina, 

 that, if these beings are to be considered 

 independent organisms, it would require 

 the creation of a new genus. 



O. Lichfensteinii (xxiii. 22-23).— The 

 Acineta varies very much both in figure 

 and dimensions. All varieties have a 

 short, thick, solid stem, dilating upwards 

 to the body of the animal. "When largest, 

 it equals half the length of the body, 

 but is at times so short that the body 

 seems as if sessile. The body is usually 

 strongly compressed laterally, and in 

 outline is a long or short oval, ovate, 

 pp'iform, or circular, except that in all 

 cases it is narrowed at its base to equal 

 in width that of the supporting pedicle. 

 In short-stalked smaller individuals, the 

 body is mostly so very shortened and 

 depressed, in its long axis, that the stem 

 is quite overlaid, and the entire being 

 has a renifonn shape. A circular or oval 

 nucleus occurs in the interior, but no 

 contractile sac was discoverable. Maxi- 

 mum length 1-18'", width 1-24'", dia- 

 meter of smallest specimens 1-96'". 



Ophrydium versatile (xxx. 8). — Stein 

 does not appear satisfied with regard to 

 the Acinetiform being to be assigned to 

 this member of the Vorticellina (Ophrj-- 

 dina). He found many cystic oval or 

 ovoid bodies, with an iri-egular central 

 nucleus and numerous chlorophyll-cor- 

 puscles in company with tliis O^jhri/dium ; 

 and along with these, which he concluded 

 to be encysted beings, other saccular 



organisms, of like size and figure, con- 

 taining also a central nucleus and many 

 chlorophyll cells, and withal furnished 

 with a large number of tapering tubular, 

 mostly curved or contorted, motionless 

 processes or tentacles, distributed over 

 the surface, recalling, in general appear- 

 ance, the " digitate Acineta.'' 



Sjnrochona gemmipara (xxx. 21-24). 

 — Stein assigns to this peculiar member 

 of the Vorticellina a very extraordinary 

 Acineta, which he has named Dendro- 

 cometes paradoxus. The body is plano- 

 convex, circular, without pedicle, and 

 gives oft' from its surface no tentacles of 

 any of the ordinary types, but one or 

 more large tubular processes, more or 

 less branched. There is so great an in- 

 constancy in the number, position, size, 

 and ramification of these processes (says 

 Stein), that two similar specimens are 

 scarcely to be foimd. The processes on 

 the same being difter also very much in 

 size and mode and degree of branching. 

 Five is the prevalent number in the 

 most fully developed forms j above six 

 are scarcely ever seen ; three or four are 

 not uncommon ; a single one is seen only 

 in undeveloped examples. An entire ab- 

 sence of such appendages is not very 

 uncommon, the nuclear developments in 

 their interior ser\'ing to identify them. 

 Neither their trunk-like process nor any 

 of its ramifications has the power of 

 lengthening or shortening itself; but the 

 whole process may imdergo a certain 

 amount of curvature, and extend itself in 

 a rigid manner. Diameter of body 1-54'" 

 to 1-25"'. 



Notwithstanding the very patent di- 

 versity in form and constitution. Stein 

 declares these tubular ramified processes 

 to be moi-phologically and physiologically 

 identical with ordinary tentacula. 



Vaginicola crystallina (xx^ai. 12-15). 

 — The Acineta attributed to this being 

 by Stein has a hyaline capsule, expanded 

 in front and narrowed posteriorly into a 

 sort of hollow pedicle. The dilated upper 

 portion is infundibuliform, urceolate, or 

 p}Tiform in figure, and is partially occu- 

 pied by the granular mass of the body of 

 the animalcule, enclosed in a membra- 

 nous sac of its own. The body is sus- 

 pended from the vaulted anterior sm*face 

 of the capsule by an intermediate gela- 

 tinous layer, which often appears pli- 

 cated. Its bulk varies extremely ; at 

 times it nearly occupies the whole ca\ity 

 of the capsule, except the prolonged 

 stem-like portion, which never contains 

 anv ; at others it forms onlv a small ball 



