INTERCELLULAR RELATIONS OF PROTOPLASTS. 
G 5 
is tliat of F. 0. Bower. * Using as plasmolysing agent 
solutions of common salt, from one to ten per cent., so 
largely used by de Vries (l.c.), Bower shows that in a great 
many cases the contracted protoplasm of parenchymatous 
cells remains connected with the cell-walls by strings of 
great initial tenuity, often only after some interval, and 
commonly slowly, thickening. In the prothallus of Nephro- 
dium villosum and Aspidium Filix-mas a two per cent, 
solution causes contraction of the protoplasm into a rounded 
mass, showing usually the smooth outline of de Vries. 
Later appear, however, delicate radial striation from the 
protoplasmic body, striation gradually extending itself to 
the cell-wall, while the striae gradually become more definite 
and resolve themselves into protoplasmic strings passing 
from protoplasm to cell-wall. Sometimes these strings are 
present from the first. In the coarser threads are often 
shown nodal thickenings. The increase of thickness of 
the threads Bower suggests may either take place from a 
supply of new material from the protoplasmic mass, or by 
lateral coalescence of the threads. Slow movement of the 
nodal thickenings away from the protoplasmic mass suggests 
the occurrence of the former ; the vibratory motion which 
the threads acquire after a time, showing diminution of 
their tension, supports this view, while the author has no 
evidence to show, though he admits the probability of, 
the occurrence of lateral coalescence of neighbouring 
threads. 
These observations the author confirms on various plants ; 
in the young flower stalks of Cephalaria riyida (allied 
material to that used by de Vries), leaves of Vallisneria 
spiralis , and of many other aquatics. In the prothalli above 
mentioned he had found that the threads ran equally to the 
free walls of the cells, and to those adjoining other cells ; this 
he confirms in the internal cells adjoining intercellular spaces 
in Pontederia ccerulea. 
All the above plants have approximately smooth-walled 
cells, and the author further proceeds to examine the cells of 
the fronds of two species of Trichomanes, in which the walls 
are pitted, in order to see if any relation exists between the 
protoplasmic threads and the pits. In the cells of these 
plants he found the threads equally to run to the unpitted 
free walls and the pitted lateral walls, and that though 
protoplasmic threads do run to pits, and threads from the 
* F. O. Bower, “ On Plasmolysis and its bearing upon the relations 
between cell-wall and protoplasm.” Quart. J. Mic. Science, 1883 
(Jan.), pp. 157-67, and plate VIII. 
