Monadina.] THE INFUSORIA. 97 



anterior extremity of the body. It is wanting of the eye 

 and tail. As the young increase in size, the parent body 

 assumes a decussated or wrinkled appearance, like a mul- 

 oerry, thus giving signs of its approaching self- division 

 into many sections (as the name Polytoma denotes), or 

 numerous individuals. Its internal organization bears the 

 usual evidences of the Polygastric nutritive system. Its only 

 organ of locomotion is the double proboscis just mentioned. 

 A large contractile vesicle may sometimes be observed 

 within the creature, which Ehrenberg conceives to be- 

 long to the male propagative apparatus. This animalcule 

 will not imbibe colouring matter. It increases by a spon- 

 taneous self-division of its body, both transversely and 

 longitudinally, thus dissolving, as it were, its berry- like 

 cluster into many individuals. It was known to Miiller 

 and Wrisberg. One species has been recognized. 



33. POLYTOMA uvella. The grape Polytoma (Monas 

 uva, M.) This creature is colourless, and has an oval or 

 oblong form, equally obtuse at both extremities. It is often 

 abundant in water, where animal matters are in solution, 

 upon which it appears to be nourished. It is generally 

 in company with species of Vibrio and Spirillum, and 

 sometimes with Uvella uva and Uvella atomus, in water- 

 butts. 



Figures 8 and 9 represent two individuals; figure 10, 

 another about to divide longitudinally ; a cluster of eight is 

 seen as fig. 7 ; and a matured one on the point of sepa- 

 rating at figure 11. Figure 9 is magnified 800 diameters, 

 shewing the double proboscis very distinctly ; and its body 

 seems enveloped in an outer tunic (probably induced by 

 the peculiar contraction), which disappears when the 



H 



