306 WALTER GARDINER. 



to cause the wall to consist as much of protoplasm as of 

 cellulose. 



It would rather be expected that if protoplasm does perforate 

 the substance of the cell wall, such perforations would assume 

 the form of fine threads, of such a degree of tenuity that they 

 could only be recognised with great difficulty, involving very 

 careful preparation and the use of very high powers. This 

 subject has already been ably dealt with by Strasburger,^ 

 whose ideas have received confirmation from TangFs^ researches 

 published in his work, on the Structure of the Endosperm Cells 

 of Strychnos, Phoenix, and Areca, and from the results I 

 myself have obtained in the pulvini of Mimosa, Robinia, and 

 Amicia.^ In my later work, which will shortly be published 

 by the Royal Society, I shall be in a position to show that, as 

 far as my investigations have as yet progressed, there has not 

 only not been the least suggestion of the presence of large 

 quantities of protoplasm in the cell wall, but also that no 

 examples of reticulate arrangement have been met with in 

 those cases where perforation actually takes place. 



I now propose to give the experiments which were made 

 with a view of testing Dr. Elsberg's results. 



Unfortunately the name of the grass he investigated is not 

 given. I examined in detail two grasses, viz. Poa nemoralis 

 and Bromus maritensis. In each case it was apparent that 

 when mounted in dilute glycerine a distinct network structure 

 could be made out in the chlorophyll grains. The boundary 

 line of each grain was badly defined, and it was very hard to 

 recognise with any certainty whether the reticulate appearance 

 was confined to the immediate substance of the grain, or 

 whether it extended beyond these limits. Indeed, in some 



' ' Ueber den Bau und das Wachstum der Zellliaute,' p. 246. 



=> Pringsheim, ' Jahrb.,' vol. xii, p. 170. 



3 'Quart. Journ. Micr. Sci.,' Oct., 1882; ' Roy. Soc. Proc.,' Nov. lltli, 

 1882. See also the conclusions arrived at by llussow from the callus reaction 

 given by the closing membrane of the nits of Plilocm parenchyma. ' Silzbcr. 

 der Dorpat Nalurfor.,' 1882, p. 350, and ' Bot. Central,' viii, 1883, p. 271, 

 also ' Strasburger Sitzber. d Niederrh Ges.' 4 Dec. 18S2, p. 12. 



