350 BOTANICAL GAZETTE [NOVEMBER 
extending from the egg into the jacket cells. In Dioon there are 
haustoria similar to those of Zamia. An examination of Cerato- 
zamia, Cycas, and Encephalartos showed that they also have haus- 
toria like those of Zamia and Dioon. The origin, development, and 
function of the haustoria, together with changes in the jacket cells 
of the surrounding tissue, would be a long problem, involving chem- 
istry as well as morphology. 
During the early stages of its growth (figs. 24-26) the central cell 
receives food material from the surrounding cells by the usual method 
of transferring substances from one cell to another. Up to the stage 
shown in fig. 25, the wall of the central cell is very thin, with no visible 3 
pits; but later the inner surface of the wall undergoes an extensive 
secondary thickening, interrupted only by the large pits which are 
such a conspicuous feature of cycad eggs. After the haustoria have 
become fully developed, their cytoplasm is in direct contact with that 
of the jacket cells, so that substances may pass from the jacket cells 
into the haustoria as readily as from one part of the jacket cell to 
another. A paper was received from Drs. Stopes and Fuyu (17) just 
as this account is going to press, describing sieve plates as found by 
GOROSCHANKIN (8). Their figures are evidently drawn from young 
material, in which the haustoria have not reached their full develop- 
ment. ‘That there is protoplasmic continuity here, as elsewhere, we 
do not doubt; but if the pit-closing membrane persists in stages like 
those shown in our figs. 37-41, it has escaped our observation. The 
haustoria project far into the cells of the jacket, and the mere thrust 
may have ruptured the membrane. At the stage shown in fig. 30; 
it is possible that the membrane may still be present; but in stages 
like figs. 37-41 we could not find any membrane, even after a reexam- 
ination of our preparations. Consequently, we see no reason for 
modifying the following account, which was written before the paper 
by Drs. Stopes and Fuyjm was received. 
The general method by which nutritive materials reach the egg 
is easily understood. The tissue of the female gametophyte is filled 
with starch and other food materials, which in a changed form pass 
into the archegonial jacket and thence into the egg. The cells of ihe 
archegonial jacket at certain times contain numerous starch grains, 
much smaller than those in the surrounding endosperm cells, but 
