Vorticellina.'] infusorial animalcules. 531 



VoRTiCELLiNA cMorostiffina {VorticfUafiscieuhta, M.) — Body greuu, 

 ovate, conical, campauulato, and annulatcd (wrinldcd). The frontal 

 margin is expanded ; the cilia contractile bladder, and green ova, are to 

 be seen, but the seminal gland, sell-division, and growth of gcmnue, 

 have not been observed. In water this creature often covers grasses 

 and rushes with a beautiful green layer. Length l-240th. ; stalk 

 five times the length of the body. 



Y.patellida (JI.) — Body hemispherical, campanulate; frontal portion 

 very much dilated ; its margin expanding greatly, and often reflexed. 

 Length 1 -480th. ; stalk about seven times the length of the body. 



V. comallaria (V. craterformis, citrina, gemella, glohularia, Maris, 

 nasuta et truncatella: Erichelys fritillm, D-ichoda gi/rinus, M.) — Body 

 ovate, conical, campanulate ; frontal portion dilated, and its margin 

 slightly expanded. It is annulatcd, and of a hyaline or whitish hue. 

 This appears to have been the iLrst infusorial animalcule discovered. 

 Leeuwenhoek, the discoverer, found it in stagnant rain-water, at Delft, 

 in Apiil, 1675. It is found in considerable abundance, upon the 

 surface of vegetable infusions, with V. microstoma, from which it is 

 distinguished by its broad front, which gives to it a bell-shaped or cam- 

 panulate appearance. Cams, in 1823, represented it as arising from 

 spontaneous generation in oil, or an accidental mixture of oil colour and 

 spring water ; but Ehrenberg remarks, the appearance arose in a very 

 natural Avay. It has been described under various names by diifercut 

 natui'alists. Ehrenberg gives thii-t}--eight references to diiFerent works 

 treating on it. Figure 237 (plate 5.) is a group of three, with the 

 pedicle of another, to shew the manner in wdiicli it is deflected 

 spirally. Figures 238 and 239 two stalkless creatures; from their 

 different appearances in the latter state, Miiller has described them 

 not only as difterent species, but under diffeient genera. In Die 

 Injmionsthierchcn, there are eighteen names imder which that author 

 has described them. Length l-43Uth. to l-24th. ; stalk six times 

 its length. 



This entertaining and well-known animalcule is usually found 

 attached to any extraneous body, as the leaves of duck-weed, small 

 a(|uatic shells, clusters of the o\ a, or the larva; of insects ; an example 

 of the latter is shewn in the Microscopic lUudrutions, fig. 30, where 



