Regeneration of Protoplasts After Wounding 143 



Regeneration is obviously an adaptation to guard against 

 the results of injuries which occur frequently in nature. 

 In such cases the higher plants usually give up the affected 

 cells; the large-celled algae and fungi, especially those 

 that have been designated by Sachs as non-cellular, evi- 

 dently cannot do that. Therefore one generally finds in 

 them the power of closing up wounds. That it would, 

 however, be of particular importance to keep escaped 

 globules of protoplasm alive is the less probable, as it is 

 only possible to do so in solutions which are quite a little 

 more concentrated than those in which the respective 

 plants naturally live. Therefore, the closing up of the 

 wound is primary, the processes in the escaped plasma 

 secondary. From the adaptive characters available for 

 the first, it ought to be possible to explain the latter. And 

 as long as the first can be explained without the hypothe- 

 sis of an independent neogenesis of the plasmatic mem- 

 brane, this assumption must be regarded as at least im- 

 probable for the latter. 



This consideration leads us to include in the field of 

 these studies even the closing up of wounds in latex-tubes. 

 The investigations of Schmidt on the latex-vessels, and of 

 Schwendener on the latex-cells may serve as important 

 points of departure in this. 28 For they teach that in parts 

 of latex-tubes which adjoin the wound of the cut, a closing 

 up of the tube can be accomplished in the same way as in 

 some Siphoneae (e. g., Bryopsis, Codium, Derbesia) and 

 in many pollen-tubes the injured part of the cell-cavity 

 is separated from the uninjured one. 29 



28 Schmidt, E. Ueber den Plasmakorper der Geliederten Milchroh- 

 ren. Bot. Zeit. 40: 462. 1882. -Schwendener, S. Einige Beobach- 

 tungen an Milchsaftgefassen. Sitsungsb. Kais. Akad. Wiss. Berlin. 

 20: 323. 1885. 



29 Schmidt, E. he. cit. p. 462. 



