596 Hill ' — The Histology of the 
A somewhat analogous case of ferment-action along ‘ con- 
necting threads * or their canals is afforded by an examination 
of the endosperm of the germinating seed of Tamus communis , 
which was described by Gardiner 1 in 1897, and the figure 
(Fig. 13, PI. XXXII) given here was drawn from one of his 
preparations. In a section of the endosperm innumerable 
fine threads bearing small median dots are seen to cross the 
thick cell-walls, but in the immediate neighbourhood of the 
developing embryo the pores or canals of the threads are 
being bored out, and the cell-walls are being gradually dis- 
solved by a cellulose-dissolving ferment, and all stages of the 
process can be seen. The ferment passes into the threads 
from the protoplasm and travels along them, causing them to 
stain more deeply and to appear thicker and more granular than 
those which are unattacked. The cell-wall around each thread 
is also slightly affected, but though no callus reaction is given, 
still the cellulose is hydrated and is stained by dyes which do 
not colour the horny cellulose of the unattacked cell-wall 2 . 
The ferment usually enters the wall on one side only at 
first and works towards the lamella, and often more than 
one thread may be engulfed in its corroding action ; when, 
or in some cases before, the region of the lamella is reached 
from the one side ferments may enter from the other side and 
eat their way to the lamella in a similar manner, with the 
result that symmetrical corrosion effects are produced (cf. 
Fig. 13, PI. XXXII). The further action of the ferment, 
which leads to the ultimate solution of the cell-wall, may 
proceed in various ways, which however do not concern us 
here ; it is clear, however, from the foregoing account that the 
effects due to undoubted ferment action in the cell-walls of the 
endosperm are to a certain extent strikingly similar to those 
which are produced during the development of the sieve-plate. 
1 Gardiner, Proc. Roy. Soc., 1897, p. 106 with diagram figure, Fig. 3. 
2 In a stirface-view of a similar wall of Tamus endosperm, appearances like the 
surface-views of Pinus sieve-plates are also obtained, for when stained with safranin 
four to seven dark points — the enlarged threads of a group — are seen to be situated 
in a pink-stained area — the hydrated cellulose, — while the rest of the wall is white 
and clear. 
