OF THE VORTICELLINA. 



587 



VoRTiCELL A nehuliferci ( V. nehuUfera et 

 I V. ConvaUaria, M. ) . — Body campaniilate ; 

 j its base, to whicli the pedicle is affixed, 

 may be either conical or hemispherical, 

 according to its state of expansion or 

 contraction ; the pedicle or stalk is about 

 five times the length of the body, and 

 can fomi as many as ten coils. These 

 creatures usually congi-egate together, — 

 though each is independent of its neigh- 

 bour J for on the approach of any foreign 

 body to one, it withdraws, by coiling up 

 its pedicle, while the others remain 

 stretched out in search of food. An am- 

 plification of 300 diameters is necessary 

 to exhibit the cilia. During longitudinal 

 self-division the body becomes broader : 

 gemmation takes place from one or other 

 side, close to the insertion of the pedicle. 

 Abundant, appearing like a white film, 

 on the stalks and roots of Lemnse and 

 other water-plants, even in winter under 

 ice. 1-570" to 1-280"- 



This is one of the species of Vorticella 

 in which Stein believed he proved the 

 development of an Acineta from the 

 encysted animal, and also, under other 

 circumstances, the generation of a brood 

 of young Monadiform beings or germs. 

 I V. citrina (M.). — More hemispherical 



! than the preceding, and the frontal mar- 

 gin more expanded. Upon Lenmae, 

 rarelv ^vith the former species. 1-430" 

 to 1-210"; stalk 3 to 4 times that leno-th. 



Perty speaks of this species as having 

 a stifi' stem, and apparently closely re- 

 lated to the genus Stentor. Dujardin 

 adopts this specific name for a Vorticella 

 defined as being very variable in form, 

 often campanulate, rarely conical, having 

 a wide projecting border, variously con- 

 torted or irregular. 



V. microstoma (xx'^^I. 1-6). — Whitish 

 grey, ovate, narrower at the ends ; frontal 

 margin not expanded or campanulate ; 

 during contraction the animal is annu- 

 lated; multiplies by longitudinal and 

 transverse (?) self-division, and by gem- 

 mation. In stagnant water. 1-2300" to 

 1-240"; stalk six times longer than the 

 body. 



This species was the subject of the 

 minutest investigations by Stein, who 

 not only represented it as becoming 

 encysted, but also as being either trans- 

 formed mto an Acineta or Actinophnjs, 

 from which a ciliated embryo is deve- 

 loped, or as giving origin, Tvdthout such a 

 metamorphosis, to a multitude of germs. 

 He remarks on the immense range of size 

 seen among difterent examples of this 

 animalcule, viz. from 1-300" to 1-3600" 



(xxvii. 5), the smallest equally with the 

 largest exhibiting the same structure. 

 The figure he describes as pear-shaped, 

 the anterior half contracted ; the ciliated 

 disc slightly everted, not campanulate; 

 rotary organ small, and elevated but 

 slightly above the periston!. He objects 

 to Dujardin's union of this species with 

 V. convaUaria, under the name of V. in- 

 fusiomim, as erroneous, the two being 

 perfectly distinct beings. 



V. Canipamda {Vorticella lunaris, M.) 

 (xxix. 1). — Hemispherical, not annu- 

 lated, bell-shaped, with the frontal mar- 

 gin broad, truncated, and not expanded. 

 Colour whitish-brown. This species ap- 

 pears like a thick bluish film upon 

 water-plants, and the single animalcides 

 are discoverable mth the naked eye. 

 1-120" ; stalk seven times longer than 

 the body. 



Perty adopts MuUer's name V. lunaris 

 for a species which he considers equiva- 

 lent both to V. Campanula and V. patellina. 



V. hauiata, — Small, ovate, hyaline, 

 attenuate at both ends ; body obliquely 

 attached to the pedicle. 1-570". 



V. chlorostigma ( Vorticella fasciculata, 

 M.). — Green, ovate, conical, campanu- 

 late, and annidated ; frontal margin 

 (periston!) expanded. Oftei! covers 

 grasses and rushes with a beautiful 

 green layer. 1-240"; stalk five times 

 the length of the body. 



V. patellina (M.). — Hemispherical, 

 campanulate ; frontal portion very much 

 dilated ; its i!!argin greatly expanded, and 

 often turned backwards. 1-480"; stalk 

 about seven times the length of the body. 



V. convallaria ( V, crater if or mis, citrina, 

 gemella, glohularia, hilaris, ?iasuta et trtin- 

 catella ; Enchelys Fritillus ; Trichoda gy- 

 rinus, M.). — Ovate, conical, campanidate, 

 annulated ; hyaline or whitish ; froi!tal 

 portion dilated, its margin slightly ex- 

 panded. This appears to have been the 

 first infusorial animalcule discovered. 

 Leeuwenhoek, the discoverer, found it 

 in stagnant rain-water, at Delft, in April 

 1675. It occurs in considerable abim- 

 dai!ce upoi! the sui-face of vegetable in- 

 fusions, with V. microstoma, from which 

 it is distinguished by its broad froi!t, 

 which gives to it a beU-shaped or cam- 

 panulate appearance. Cams, in 1823, 

 fancifully represented it as arising from 

 spontaneous generatioi! in oil, or froi!! 

 an accidental mixture of oil colom* and 

 sprii!g-water. It has been described 

 under various names by different natu- 

 ralists. 1-430" to 1-24" ; stalk six tii!!es 

 its lenofth. 



