378 MR. 8. LE M. MOORE’S STUDIES 
as in any way related to the transport of nutrimental substance, 
and for the following reasons :— 
(1) The assimilated matter produced at or near the equator 
of palisade-cells not laterally connected must pass along these 
cells’ side before arriving at a septum: they must thus move 
upon a chlorophyll-paved road, so that the grains cannot inter- 
pose any efficient obstacle to the passage. If the cells are in 
contact, lateral movement of assimilated material might occur; 
but the position of the chlorophyll would, on Haberlandt’s hypo- 
thesis, render this difficult, if not impossible. 
(2) Such a case as that shown in fig. 7 of Haberlandt's 1886 
memoir* (reproduced here as fig. 33) does not harmonize with 
his theory so far as regards the vertical septa, since the supposed 
advantage derived from keeping the walls free from chlorophyll 
would favour a lateral passage of assimilated matter. 
(3) The arrangement of the chlorophyll upon the periphery of 
palisade-cells is an expression of the fact that the greater part of 
the protoplasm is situated there; since, were streaming to take 
place from here to the transverse walls, the grains would thereby 
he shifted on to these walls—a very rare occurrence. Now, upon 
De Vries’st theory, which seems well founded and to which no 
objection has, I believe, been taken, the transport of assimilated 
matters is facilitated by circulatory and rotatory movements of 
protoplasm, movements in which the chlorophyll grains are pas- 
sive participants. How, then, is it possible to see in the almost 
or entire absence of streaming from certain parts of a cell à 
means whereby rapid transport is effected there ? 
(4) Before the validity of the theory in question can be 
admitted, it must be shown that the chlorophyll ranged upon 2 
cell-wall really blocks the passage of assimilated material there- 
through. One difficulty in the way of accepting this view has 
already been adverted to: might one not as soon expect to 
arrest the current of a river by mooring a few boats across it, a8 
that protoplasmic streaming should be stopped by the interposi- 
tion of isolated chlorophyll grains ? 
(5) But the large number of exceptions to the supposed rule 
puts great difficulty iu the way of recognizing it as such. Taking 
mesophyll first of all, what do we find? In diffused light of 
medium intensity the grains are in epistrophe, the septa being 
* Ber. d. deutschen bot. Gesell. 1886. 
t Bot. Zeitung, 1885. 
