Ji'icilhvia.'] TNFrsoin\L animalcules. 223 



continually moving cAen protruding organs immediately behind the 

 openings, and they are endowed with transverse self-division. Eut 

 all plants, says EluTnberg, which are endowed with vohmtary 

 motion, open oiificcs, feet, and self-division, we may look upon as 

 animals, without waiting to see them eat. That this last resolution 

 is correct, no doubt all botanists will accede to ; but the follomng 

 considerations are those which incline to the opinion of the vegetable 

 nature of the Clostcrina. The sti-uctiu-e of the Closterina is evi- 

 dently that of the Conferva, as well as the formation of their spores 

 or seeds, and the development of them. The existence of amylum 

 (starch) within the Closterina is a stiiking proof of their vegetable 

 nature. They are likewise destitute of feet, for what Ehrenberg 

 took for these appendages are self-moveable molecules, as are seen in 

 CHosterium trahecula, to the number of 500 or 600, or more, and 

 filling a canal rimning along the whole length of the plant. The 

 fiinction of these bodies it is very difficult to determine ; but they 

 are to be found in very many Conferva, and are perhaps to be likened 

 to the spermatic animalcules of plants. 



" Under the great family BaciJlaria, Elircnberg has brought 

 thirty-five to tliirty-six genera ; but which may be more properly 

 divided into two separate families — the family of the true BacUlaria, 

 and that of the Besmidiaeea. This last family has already been firmly 

 settled by Menegheni, and includes those irvie Algae, concerning whose 

 nature there can be no doubt. To the ti'ue Algae belong the fol- 

 lowing genera of Ehrenberg' s BacUlaria : — Besmidium Ag. ; Sfauras- 

 tnun, Mey. ; Pentasterias, Ehr. ; Sphaerastrum, Mey. ; Xanthidium, 

 Ehr. ; Scenedesmus, Mey. ; Odontella, Ag. ; Pediastrum, Mey. {Mi- 

 crasterias, Ag.) ; and EtMstrmn, Ehr. In all these genera, nothing 

 has yet been observed which can be adduced as evidences of their 

 animal nature. Actual motion, arising from internal causes, I saw 

 only in Sphaerastrum ; and the slight movement, supposed to have 

 been observed in some of the genera, is certainly of the same 

 description as that of some Conferva, which sometimes vegetate far 

 below, at other times upon, the surface of water ; but this elevation 

 from the deep is generally connected Avith visible evolution of gaseous 

 matter. The increa,se by self-division occurs in all these genera ; 

 this process is looked upon Ity Ehrenberg as one of the strongest and 



