ON THE INTERCELLULAR RELATIONS OF PROTOPLASTS. 147 
be seen that the middle lamella, separating the widened 
bases of the pits in adjoining walls, is penetrated by fine 
threads passing from pit to pit (see Fig. B). While the more 
median of these threads appear to pass in a straight line from 
pit to pit, the lateral ones are progressively more and more 
curved, so as to make the figure described by the outermost 
elliptic, or even almost circular. (The same relations are 
visible in the threads passing through the normal thick parts 
of the walls in Strychnos nux-vomica .) The threads are 
brought out with still greater clearness when, prior to treat¬ 
ment with chlorzinc iodine, the section has been laid in 
potassium iodide iodine. 
In Phoenix dactylifera sections of the endosperm taken 
parallel to the surface of the seed, as well as at right angles 
with it, first saturated with potassium iodide iodine solution, 
and then allowed to swell in chlorzinc iodine, show a 
structure analogous if not similar. The thickened walls of 
the cells show numerous strongly-marked pits, corresponding 
in position in adjoining walls. The untliickened wall 
separating the bases of the pits, stained feebly yellow, is seen 
clearly to be pierced by dark yellow or brownish rods. These 
rods, likewise, are protoplasmic in nature. 
It will be seen, therefore, that Tangl claimed to have 
found in these seeds evidence of protoplasmic continuity of 
a clear kind. In Stnjchnos mix-comica the protoplasmic 
threads pass through the thickened wall at, practically, any 
point of its periphery, exceptiug perhaps at the actual angles 
of the cells, and are of extreme tenuity ; while in the case of 
Areca oleracea and Phoenix dactylifera the threads are some¬ 
what coarser, in the latter notably so, and pass only through 
the unthickened parts of the cell wall, i.e. through the closing 
membrane of the pits. 
While carefully guarding himself against the suggestion 
of the general occurrence of such protoplasmic threads even 
in the group of palms, Tangl closes his memoir with the 
following important sentences :— 
“ Ueberblicken wir die gewonnenen, in der vorliegenden Abhandlung 
niedergelegte Besultate der Untersucliung, so wird durcli dieselben die 
Thatsache festgestellt, dass die verdickten Membranen des Endo¬ 
sperms einiger Samen von einem System von Verbindungskaniilen 
durckzogen werden, durcli welcke eine offene Communication zwiscken 
benaclibarten Zell-elementen und ein continuirlicker Zusammenliang 
ilirer Protoplasma-kOrper liergestellt wird. 
Der Umstand, das die Darstellung des bescliriebenen Baues in den 
verdickten Membranen des Endosperms in systematischer Bezieliung 
sehr weit abstekender Piiauzen gelungen ist, darf der Hoffnung 
berechtigen, dass wir demselben aucli nock bei anderen Objecten 
begegnen werden.” 
