Regeneration of Protoplasts After Wounding 141 



of a cell-membrane around exuded masses of protoplasm. 

 He stains the water or the diluted solution in which the 

 threads are cut through, with Congo-red, which is stored 

 up with great avidity by these young cell-membranes. 



Nevertheless this method does not yet decide the ques- 

 tion raised by me, because, as Klebs also says, there is no 

 means of deciding the presence or absence of a plasmatic 

 membrane on a portion of the mutilated protoplast that 

 forms a cell-membrane. "Among the free swimming balls 

 of protoplasm there are always a number of such that are 

 quite large and rich in contents which live several days 

 but without forming a cell-membrane." In the case of 

 most of them, however, the beginnings of the formation 

 of a cell-membrane are very soon evident. 25 Wherein 

 the difference in the behavior of these two kinds of frac- 

 tional parts consists, was not further investigated by 

 Klebs. My assumption that the former lacked the limiting 

 membrane, while the latter got a part of this organ when 

 cut off, has not been at all disproved. 



Nor does the great extensibility of the plasmatic mem- 

 branes during the enormous swelling of the vesicles which 

 later form the cell-membrane seem to me by any means 

 improbable or even surprising. Plasmolytic experiments 

 teach us at every step that the extensibility, not only of 

 the plasmatic membrane, but also of the wall of the vacu-, 

 oles and perhaps even of the granular plasm is very con- 

 siderable. And Went has comprehensively demonstrated 

 that the swollen spheres of Vaucheria contain only such 

 vacuoles as have originated by the enlargement, and 

 mostly also by division of the sap-vesicles present in the 

 uninjured plant. The assumption of an extensibility of 

 the plasmatic membrane which need not be much greater 

 than the proven elasticity of the wall of the vacuoles can- 



* r *Loc. dt. p. 507. 



