IV. On the continuity of the protoplasm through the walls of vegetable cells. 5 1 
the least intimately connected to the cell-wall, and the shrinking does not 
exlend to the whole protoplasmic body. 
III. Criticisms and Gonclusions. 
As may be readily imagined liiere are olher observers besides myself 
who have investigated the subject of the continuity of the protoplasm be- 
tween the walls of adjacent cells. On Tangl’s results and Russonv’s rnost 
excellent paper I have no observation to make, sinee it is hardly necessary 
for me to say that I regard them as in every wav satisfaetory and conclusive. 
It only remains for me to criticize the papers of three olher investigators viz. 
Frommann 1 ), Eisberg 2 3 ) and IIu.i.hoise :! ). As I have already dealt at some" 
length with the investigalions of Frommann and Elsberg in my paper "on 
some recent researches on the continuity of the protoplasm through the 
walls of vegetable cells“ 4 ), I need here only allude to the principal poiuts 
which these observers attempt to establish, and at the same time give my 
ow n results and opinions upon them. Briefly stated the principal facts in- 
volved in Frommann’s Statements are: That open passages of very appreciable 
size are of very frequent occurrence in the common cell-wall: That Chlo- 
rophylle corpuscles and protoplasmic reticula occur imbedded in its sub- 
stance: That the intercellular spaces may contain protoplasmic granules and 
networks: That these networks of protoplasm may be traced into the cell- 
wall, and are particularly clearly defined in the case of the epidermal cells, 
running from the cell lumen out into the cuticle. Although l was aware that 
every one of these Statements would be received with some surprise by 
almosl any botanist w ho is at all acquainted with the histology of tissues, 
I investigated in as careful a rnanner as possible those particular tissues in 
which Professor Frommann had obtained his most favourable results namely 
in the leaves of Rhododendron ponticum and Dracaena draco. Having shown 
that, as far as I was able to observe on treatment with Jodine and Chlor. 
Zinc. Jod., a pit-closing-membrane was present, I pointed out the extreme 
improbability both on morphological and physiological grounds that chlo- 
rophyll-grains should be imbedded in the substance of the cell-wall, and 
meutioned that it was hardly necessary to state that after the most careful 
examination no such case was observed. Numerous preparations treated and 
stained in various w ays, showed no signs of tbeir being either granules or 
nets or finally any protoplasmic structure whatsoever in the inlercelluiar 
spaces. I theu dealt with the possibi lity of follow ing the protoplasmic struc¬ 
ture into the substance of the cell-wall. Since Professor Frommann’s obser- 
1) Frommann. ticob. über Structur und Bew. d. Protoplasma der Pflanzenzellen 
Jena 1880. 
2) Elsberg. Quart. Journ. Micr. Sei. Jan. 1883. 
3) Hillbouse. Bot, Central XIV. 1883. In Nr. 89—94. 124. 4. 
4) Gardiner. Quart. Jour. Micr. Sei. March 1883. 
Arbeiten a. d. bot. Institut in Würzburg. Bd. III. 6 
