1908] BRIEFER ARTICLES 301 
of the mycelium next to the fruit bodies becomes very thick, also that of 
the entering germ-tube, while the wall of the zoospore in all of the plants 
remains as a small trumpet-shaped expansion of the end of the tube on 
the surface of the host. Starch grains are abundant in the larger portions 
of the mycelium and in the sporangia. The wall of the resting sporangium 
consists of three layers, the inner being laid down by the protoplasm after 
its accumulation in the main part of the plant body, and is thus not con- 
tinuous with the mycelium which, however, usually becomes plugged after 
the withdrawal of the protoplasm. The walls of the resting sporangia are 
yellow at maturity, while the content is dark red. 
The temporary zoosporangia have a thinner wall than that of the resting 
sporangia, and at maturity develop a stout exit tube, the end of which 
opens by a pore, the margin of which grows inward by invagination. The 
200spores when swimming rapidly are elliptical in form, with the red oil 
in minute drops at the forward end, where are the two cilia. As they slow 
down they become rounded and are 8-10 p in diameter. 
LAGERHEIM considered this plant to be an alga devoid of chlorophyll, 
though Linpavs3 says that on account of the lack of chlorophyll it cannot 
be classed with the algae. 
The alga to which Rhodochytrium appears most closely related, 
according to LacERHEIM, is Phyllobium, discovered by Kiess+ (Phyllo- 
bium dimorphum in leaves of Lysimachia nummularia and more rarely in 
Ajuga repians, Chlora serotina, and Erythraea centaurium; Phyllobium 
mcertum in dead Carex leaves). It is an intercellular parasite and P. 
dimorphum has also a definite relation to the vascular bundles. In this 
Species the enlarged portion of the plant body contains chlorophyll in the 
Protoplasm, as well as a reddish-yellow oil and starch. The branched 
thizoid processes are devoid of chlorophyll. Resting spores only are 
known. They are packed with the reddish-yellow or orange-red oil and 
Starch and possess a thick wall with several layers. The zoospores are 
biciliate. 
A more extended paper is in preparation, dealing fully with the question 
of development, morphology, physiology, and cytology of this remarkable 
Plant. This note is published in the hope that it will stimulate a searc 
‘pon the ragweed and other possible hosts for this parasite, and I should 
Consider jt a great favor to receive material from different observers in 
ase it is found.— Gro. F. ATKINSON, Cornell University. 
* ENcLER an PRatL, Pflanzenfamilien 1°*#:528. 1900. 
as = G., Beitrige zur Kenntniss niederer Algen formen. Bot. Zeit. 39: 249- 
? 295-272, 281-290, 297-308, 313-319, 329-336. pls. 3, 4. 1881. 
