from the Cell-contents of the Characese. 115 



9, 10) ; and not only in SpirogyrUy but also in the dead bodies of 

 some of the Furcularian Rotifera (fig. 16). To what infusorium 

 this cell belongs I am ignorant ; but from having seen it associ- 

 ated with Astasia under circumstances indicative of one being the 

 product of the other, and more particularly from finding young 

 Astasi(je developed in the cells of Spirogyra to a great extent 

 where the tubulating cell- development was equally prevalent 

 (fig. 9), with no mother-cells present in the cell of Spirogyra 

 containing the young Astasia to thus account for their origin 

 (fig. 9 d), I have supposed that they might have come from the 

 germs contained in the tubulating cells, which germs have been 

 conveyed into the cells of Spirogyra in the way above described 

 (fig. 10). However, whether the tubulating cells are connected 

 with Astasia or not, young Astasia are also developed within 

 the cells of Spirogyra to a great extent (fig. 9 c?); and although 

 they at first have almost as much polymorphism as an Amoeba, 

 still they retain their cilium, and after a while assume the form 

 and movements peculiar to Astasia (fig. 9 dJ). I might here 

 mention, that on one occasion I saw a large Amoeba with a long 

 cilium, at one time assuming the form of Astasia, and at another 

 that of Amoeba, which thus gives us the link between these two 

 infusoria. The cilium however had not the power of the filament 

 of Astasia, though it occasionally became terminal. 



Besides these developments in the cells of Spirogyra, there is 

 the one described by Professor Pringsheim*, and frequently a 

 development of long, slender, colourless filaments, which have a 

 writhing movement like that of an injured earth-worm. Some 

 of these filaments present numerous granules in their sheath, 

 and a faint appearance of cell-division ; and I think that I have 

 seen such filaments coiled up in mother-cells within the Spirogyra- 

 ceU. The same kind of filaments occasionally appear in Clos- 

 terium acerosum, when its contents are passing into dissolution ; 

 but long before the chlorophyll has changed colour, or putre- 

 faction has commenced. To enumerate all the developments of 

 this kind, however, which take place in the filamentous Algae 

 is not my present object, and the only other development of the 

 kind that I need allude to here is that which frequently occurs 

 in Euglena. 



This is also of a Rhizopodous character, and at first I thought 

 it might be merely another form of Euglena, as Acineta is but 

 another form of Vorticella; but subsequent observations con- 

 vinced me that this was not the case. I was led to notice this 

 development by an apparent metamorphosis of the cell-contents of 



* Ann. & Mag. of Nat. Hist. vol. xi. p. 210, 1853. 



8* 



