Mr. H. J. Carter on the Oryanizatinn of Infusoria. 129 



and the appearance of a plurality of vesicul?e. That, also, the 

 sinuses which are in the immediate vicinity of the vesicula do 

 empty themselves into it may be easily seen, when both are 

 present ; and what takes place near, it seems not unreasonable 

 to infer may, through a concatenation of communication, take 

 place from a distance. At the same time, the sinuses of this 

 system in the sarcode of Amwha not only seem to burst into 

 each other, and into the vesicula, but when the latter has con- 

 tracted, another sinus, partially dilated, and situated near the 

 border, may be seen to swell out and contract after the same 

 fashion, before the reappearance of the vesicula (fig. 81 a a). 

 Then there is no knowing how many vesiculse there may be in 

 Amoeba ; v/hile Actinophrys Sol, Ehr., is surrounded by a peri- 

 pheral layer of vesicles, which, when fully dilated, appear to be 

 all of the same size, to have the power of communicating with 

 each other, and each, individually, to contract and discharge its 

 contents externally as occasion may require ; though, generally, 

 one only appears and disappears in the same place. In Oxytricha 

 the vesicula is single or dual, but in Plasconia, as far as my 

 observation extends, always single. The vesicula is always 

 single in Vorticella, where it is attached to the buccal cavity 

 close to the anal orifice, as in Rotifera and the young of Cyclops 

 quadricornis (fig. 74/, h). In one species of Vorticella there is 

 a distinct pouch for these excretory orifices, about half-way up 

 the buccal cavity (fig. 75 a). In Colepina the vesicula occupies 

 the posterior extremity. 



Its existence in Astasia, Anisonema, and Euylena can only be 

 determined by inference. They all have a transparent vesicle 

 situated close to the anterior extremity ; and in Astasia we know 

 that it is thus situated close to the buccal cavity (fig. 45 e). In 

 Anisonema it seems to alter in size and shape, as it does in some 

 Amoeba, without completely contracting ; and in Astasia also it 

 is at one time more defined and apparent than at another; 

 but this may be owing to change of position in the entire ani- 

 malcule. In Polytoma Uvella it is similarly situated, but double, 

 and has been seen to contract by Schneider*; and in a small 

 colourless animalcule, very much like a young Astasia, as well 

 as in a minute species of Chlamidomonas, Ehr., I have frequently 

 seen this vesicle contract and dilate in the manner of the vesicula ; 

 so that there can be little doubt about the vesicle in the anterior 

 extremity of Astasia, Anisonema, and Euylena (fig, 49 b) being 

 the homologue of the vesicula, though in the latter the red body 

 be appended to it ; this, however, is not the case in the Chlami- 

 domonas mentioned, where the red spot is nearly in the middle of 



* Ann. & Mag. Nat. H^i^t. vol. xiv. p. 322, 1854. 

 Ann. ^ May. N. Hist. Ser. 2. Vol. xviii. 9 



