434 M. Eckhard on the Organization 



scattered, and are only to be fonnd in the large works on Infu- 

 soria), and, on the other hand, that I have made some new obser- 

 vations, which may probably possess interest. 



2. Before passing on to the true demonstration of the rela- 

 tions of their organization, I must examine more minutely an ex- 

 pression of Siebold in the work above quoted. It is as follows 

 (p. 7) : " But those infusoria which remain as Polygastrica (after 

 the separation of the Rotatoria) require a further limitation, be- 

 cause those organisms which are enumerated among the Closterina, 

 Bacillarina, Volvocina, and probably many other of Ehrenberg's 

 animals, having stomachs but not intestines, must be referred to 

 the vegetable kingdom." The dispute regarding the nature of 

 these bodies is old, and dates from the time of their discovery. 

 It has been renewed innumerable times, by both zoologists and 

 botanists ; nevertheless the truth is apparently not yet deter- 

 mined. Both manuals of botany and zoology frequently contain 

 one and the same genus, or in fact, family. I fear that again to 

 bring forward the question will be irksome to those who have 

 long since satisfactorily proved the animal nature of the supposed 

 plants, but I cannot refrain from so doing. It therefore first be- 

 comes requisite to attempt to restore to their proper place the 

 three families referred by Siebold to the vegetable kingdom. 



I. Closterina. — The grounds for their being of animal nature 

 are derived partly from their motion, partly from their organi- 

 zation. On the leaves of Ceratophyllum, I observed the manner 

 in which several Closteria adhered elegantly by one extremity ; in 

 about a quarter or half an hour many of them were situated in 

 the same manner upon a higher part of the leaf : not a single 

 animalcule was found on the side of the leaf, nor adherent longi- 

 tudinally to it. They had evidently moved during the above 

 time from the lower to the upper part of the leaf. If we observe 

 their motions under the microscope, they are not so rapid as 

 those of many other polygastric infusoria, but the motion is 

 always evidently animal. They swim, especially in summer, in 

 the most varied directions, and I have frequently seen CI. acero- 

 sum and Lunula swim against the current when the water on the 

 object-holder was flowing towards one side, whilst fragments of 

 plants, various kinds of Spirogyra and Oscillatoria, were carried 

 away. It is difficult here to discover anything but animal 

 motion; to explain this however by electricity, as Turpin at- 

 tempted*, is unnatural, and not less absurd than that of the mus- 

 cular fibre by the same natural agent by Strauss. But the relations 

 of the organization of the Closterina are likewise in favour of their 

 animal nature. In illustration of this I shall confine myself to 



* Sur les Closteries. 



