and Reproduction of the Polythalamia. 315 



Now, I regard the contractile substance of all the larger 

 llhizopoda as such naked, free, contractile protoplasm. Whether 

 it has been produced from one or several cells is a matter of in- 

 difference at present ; it is protoplasm, and thus its nature and 

 origin are characterized. It is by no means improbable that in 

 individual cases it may have been produced by the coalescence of 

 several naked masses of protoplasm with nuclei — that is, from 

 several cells ; but this coalescence is at any rate so complete, 

 that only the number of the nuclei, which would probably be 

 persistent in this case, could indicate that of the previously 

 existing separate cells ; in the protoplasm itself no division into 

 cells is to be perceived. For as the coalescence of the processes 

 outside the shell is complete (as is shown by the observation 

 of any Gromia, and has been confirmed repeatedly since my first 

 detailed statements), and as this coalescence exactly resembles that 

 of the protoplasm-threads in vegetable cells, of course, if several 

 originally distinct masses of protoplasm contribute to the forma- 

 tion of the contractile mass of the body of a Rhizopod, these 

 will become completely amalgapiated to form a homogeneous 

 mass. For whenever protoplasm coalesces — whenever the indi- 

 viduality which a mass or thread of this substance possesses 

 during life, and endeavours to preserve externally with a certain 

 degree of obstinacy, is overcome, we can no longer speak of an 

 individuality in the coalesced protoplasm-masses. 



To give a well-ascertained example of such coalescence of 

 membraneless cells, I may refer to JEthalium septicum among 

 the Myxomycetes. According to De Bary's statements*, which 

 I can confirm, the structures of this name occurring in tanners' 

 bark consist of a substance like the Amoeba; to express their 

 nature with perfect clearness, they are naked protoplasm-masses, 

 of course with the proper nuclei. They are sometimes large, some- 

 times small ; they divide and coalesce as is required by the soil 

 upon which they move, and internal circumstances of the sub- 

 stance, which are beyond the sphere of observation. The Amoeba- 

 like movements are perceptible under the microscope at every 

 free margin ; and if we succeed in isolating very lively substance 

 in a capsule with water, it presents the most remarkable 



the cell retain its " mouth : " there remains an orifice in the cell-membrane 

 through which the protoplasm communicates with the external world. The 

 DifflugioE, Euglyphce, and all Monothalamia may be explained as cells of 

 this kind, with a membrane, and an opening in the latter. Such cells also 

 occur in higher organisms. E. Briicke, and, after him, Brettaner and Steinach 

 have regarded the epithelial cells of the intestine in this light, and, it appears 

 to me, quite correctly. 



* Siebold and KoUiker's Zeitschrift, Bd. x. p. 88 ; Ann. and Mag. Nat. 

 Hist. vol. V. 3 ser. p. 233. 



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