IX VEGETABLE BIOLOGY. 241 



Studies if Vegetable Biology.— IX. The alleged Existence of 

 Protein in the Walls of Vegetable Cells, and the Micro- 

 scopical Detection of Gluco^ides therein. By Spencer 



Le M. Moore, F.L.S. 



[Read 18th June, 1891.] 



In his first memoir on callus * the author alluded to the views of 

 AViesner and Krasser upon the constitution of the cell-wall, more 

 especially as regards the question whether protein is or is not 

 present therein. The bibliography of the subject having been 

 given in that memoir, there is no necessity to present it again ; 

 as regards the new theory itself, it must suffice to say that 

 "Wiesner and Krasser and their followers, mainly on the ground 

 that proteid reactions are frequently yielded by the walls of 

 vegetable cells, hold such reactions to indicate the presence of 

 protein ; whereas Klebs, Fischer, and those who agree with them 

 maintain the improbability, if not impossibility, of these re- 

 actions being due to protein, the latter writer suggesting that 

 tyrosin may be the substance sought for. Wiesner's deduction 

 from Krasser's microchemical studies — his dermatosome theory 

 of cell-wall structure — has already evoked much controversy, 

 and has had to bear the brunt of some damaging criticism, 

 principally on the part of Klebs and Fischer. But although we 

 may be led to differ in toto from the conclusions reached by the 

 Austrian botanists, we ought not to repudiate our debt to them 

 for starting a discussion and inviting research upon a matter 

 which, it may be affirmed with certainty, will not be allowed to 

 rest until some diminution has been brought about in our at 

 present rather disreputable ignorance concerning the chemical 

 constitution of the cell-wall. 



At first sight it would seem an easy task to find out whether 

 or no protein be a constituent of the walls of a tissue, since by 

 the action of a peptic or pancreatic fluid we ought to be able to 

 peptonize out the protein, after which proteid reactions should 

 fail. The first batch of experiments, presently to be described, 

 were made upon this assumption; but I now think the re- 

 sults yielded by them are not so conclusive as they formerly 

 appeared to me ; for apart from the possibility of the supposed 

 proteid or proteids in the wall being per se unpeptonizable, it is 



Journ. Linn. Soc., Bot. vol. uvii. p. 521. • 



