I40 BOTANICAL GAZETTE [FEBRUARY 
with the vessels, exactly as described by LAGERHEIM and ATKINSON 
(fig. 5), and probably draw water from them. These terminal 
haustoria (fig. 6) are closely appressed to the thin places between 
the spiral thickenings of the vessels, but appear not to penetrate 
them as in the phloem. 
With the development of the rhizoids the protoplasmic contents 
of the cysts become more abundant and denser. The nucleus 
increases in size and undergoes a metamorphosis like that of the 
zoosporangium described below. Starch grains, if not already 
present, appear and become large and abundant, until they pack 
the cyst so full that its cytoplasmic contents proper may become 
almost invisible. In this process all vacuoles disappear and 
apparently all surplus water is eliminated. Even the aqueous 
karyolymph partially disappears, causing the nucleus to collapse 
(figs. 7, 8). In this condition the nucleus differs so far from 
ordinary healthy nuclei that it is difficult to believe that this change 
is not pathological. But it seems to be a universal and perfectly 
normal phenomenon. On the beginning of germination in the 
spring, the nuclei again become turgid, though they are apparently 
smaller than before shriveling up. 
When the vegetative activity of the parasite is ended, s 
indicated by the shriveling of the nucleus and the withdrawal of 
all of the starch from the rhizoids into the spore, a second cellulose 
wall is laid down on the inside of the spore (fig. 7) and sometimes 
in the proximal ends of the rhizoids as well (fig. 5). But either 
at the time of deposition of the second layer of the spore wall or 
soon afterward, the rhizoids are cut off from the spore first by a 
plasma membrane and later by a definite wall. This is soon 
followed by the disorganization of the contents of the rhizoids. 
The second wall of the spore is quickly followed by the formation 
of a third (fig. 8), a thick, non-cellulose endospore, which completes - 
the preparation of the spore for its period of rest. 
The starch grains 
One of the most interesting things about Rhodochytrium is the 
fact that though it is a parasite and has completely lost its chloro- 
phyll, it forms starch in considerable quantities. The source of 
