118 DESCRIPTION OF 



organisms are in his opinion of vegetable origin, and more especially 

 embrj^onic forms, sucb as spores of various Confei"V8e, of Vaucberia, 

 &c. That eminent comparative anatomist states, (Anatomie der 

 Wirbellosen Thiere, Book 1st., p. 8. Berlin, 1848), that "ciliated 

 organs occur in the vegetable kingdom, in the form of ciliated 

 epithelium in the spores of Vaucberia, and in the shape of long 

 filiform isolated fibres, in the spores and early stages of existence of 

 several species of Confervae ; many of which organisms indeed, 

 Ehrenberg has described as belonging to the families Monadina, 

 Vohocina, «S:c." 



The active movements of the Vohocina are identified with those of 

 plants, and, to Siebold's mind, distinguished from those of true animal 

 Infusoria, such as the Kolpoda, by entirely wanting a voluntaiy 

 character. 



Another distinction, separating such genera ft'om the animal 

 series, the same naturaKst finds in the unalterability or fijdty of 

 their general outline, all animals having the power of varpng their 

 outline, by the contraction or expansion of their substance. 



M. Dujardin, although admitting generally the animal nature of 

 the families in question, differs very materially from Ehrenberg, in 

 his views respecting their organization. 



The third order in the classification of this naturalist which in- 

 cludes the Monadina, Vohocina, Dinohryina, TJiecamonadina, Euglena 

 and Peridinia, has for its common characteristic the existence of one 

 or of several flagelliform filaments, serving as locomotive organs. But, 

 Dujar din's definition of the family of Monads difi'ers widely fi'om 

 that of Professor Ehrenberg, in assigning no mouth or digestive sacs, 

 and in attributing to them a form generally variable, and a capa- 

 bility of contracting adhesions to one another, owing to their soft 

 gelatinous bodies being unprotected by any epidermis. Dujardin, 

 moreover, cannot admit the red specks to be eyes. 



The apparent sacs he terms vacuoles (vacuolse), and considers 

 them to be spontaneously hollowed out in the body of the animal, 

 and when, as usual, near the surface, to open externally, and on again 

 contracting, to enclose any foreign particles which may have intro- 

 duced themselves. According to the French micrographer, therefore, the 

 Monadina are nourished only by absorption, effected by their external 

 surface, and, in some measure, by the spontaneously formed vacuolae. 



