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IN VEGETABLE BIOLOGY. 521 



Proteids : the substance of the -BaZ/Za-stoppers most closely re- 

 sembles Lardacein. 



8. The function of the callus, both of the Vegetable-Marrow and 

 of Ballia, is to moderate the flow of proteids and direct it so that 

 all the growing-points shall receive their due amount of the 

 necessary pabulum. That the stoppers function as sealers-up of 

 the pit is shown by the coincident growth of pit and stoppers. 



9. Many of the phenomena presented by the dissolution and 

 renewal of callus-masses upon sieve-plates recall to mind the 

 action of ferments. In these cases it is, in all probability, a 

 callolytic (proteolytic) ferment to which the effects are to be 

 ascribed. This ferment has not yet been isolated. 





Note 







-In the discussion which followed the reading of the above 

 memoir, one of the speakers referred to "Wiesner's * theory of 

 cell-wall structure and to the observations relating thereto of 

 •K-rasserf and Klebs J. It has been mentioned in the memoir 

 that attention was paid to the proteid reactions of the wall, with 

 the result that neither with the Vegetable-Marrow nor with 

 Ballia did Millon's reagent or Copper Sulphate and Caustic 

 "otash produce the slightest change of colour. Under these cir- 

 cumstances, I did not see the bearing upon the question of the 

 above-mentioned researches, and I fail to see it now in the case 

 °» Vegetable-Marrow callus, which, since it is soluble in a gastric 

 fluid, can obviously have no genetic relation whatever with the 

 Wall. With Pallia, however, it is different, and I am obliged to 

 Prof. J\ w. Oliver for his reference to the subject. It is open to 

 any one to argue thus : — " True, the evidence brought forward that 

 the stoppers are not formed by swelling-up of the wall is decisive; 

 but when it is remembered how frequently the cell-wall contains 

 either proteids or some nitrogenous substance or substances 

 derived directly from destructive metabolism of proteids, it has 

 not been proved that the stoppers, although they are deposited 

 at the pit's mouth by the protoplasm, may not consist of a carbo- 





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Wiener Akad. Band 93. t Bid. Band 94. 











t Bofc, Zeitung, 181 



Haw. Jnim* BOTANY, VOL. XXVII- 2 o 





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