666 DESCRIPTION OF [Botatoria. 



cesopliagcal tube, but is suiTounded by a cellular glandulose turbid 

 mass ; one species has a conical, tubular, alimentaiy canal, without 

 the surrounding mass or expansion at the end ; the four European 

 species have two spherical alimentary glands, and an ovarium, mth 

 a few large ova ; occasionally these species are viviparous. In three 

 of them a contractile vesicle is present. In R. macnirus, near the 

 alimentaiy canal, are two glands. In three species from nine to 

 twelve parallel transverse vessels have been obseiwed by Ehrcnberg j 

 and besides these, in the four European species, styliform respiratory 

 tubes, emanating from the neck, which in one species are ciliated 

 anteriorly. The indications of a nervous system are two red frontal 

 eyes, in the four Eiu-opean forms ; and beneath them, in R. vulgaris, 

 are two ganglia. 



EoTiFEE vulgaris ( Vorticelh Rotatoria, M.) — This creature, which 

 was discovered by Leeuwenhoek, has a fusiform white body, gradually 

 attenuated towards the foot ; the eyes round. " This animalcule was 

 described and illustrated in the Ilicroscopie Cabinet some years ago, 

 and prior to the appearance of Ehrenberg's observations. It has the 

 power of contracting or extending the length of the body in the 

 following remarkable manner : — When the creature is about to 

 shorten itself, transverse folds or joints are observable, Avhich do not 

 appear to be confined in number or situation ; the integuments, when 

 a joint is produced, are drawn within the parts above, and slide out 

 like the tubes of a telescope, when the joints disappear. It is this 

 power that enables it to assume the form of a sphere, the head and 

 tail being drawn within the body." Anteriorly it has a proboscis- 

 like process, with a ciliated extremity, and a soft hook ; near its end 

 are two dark red points. The body terminates in a moderately-long 

 tail-lilce foot, having six processes, disposed in pairs ; two wreaths of 

 cilia (the Avheels), voluntarily moveable, are placed upon short thick 

 arms (pcdicled), which can be drawn in and out at pleasure ; these 

 A\ reaths serve for swimming and purveying, the food approaching the 

 mouth by the currents produced in the water by the cilia. On the 

 dorsal surface is a styliform horn {Speculum collar e, M.) destitute of 

 cilia at its end. During vibration the neck has a cii'cular fold, ap- 

 pearing like lateral styles. Eoui- longitudinal muscles, two anterior 

 and. two posterior, arc seen ; laterally, also, two club-shaped, for 



