154 BOTANICAL GAZETTE [FEBRUARY 
Nutt. is described by Wo r* in the same journal. It infects the leaves, which 
it causes to fall. 
An interesting organism belonging to the small group of parasitic slime 
molds (Phytomyxaceae) is described by SCHWARTz” as occurring on the roots 
of some species of the Juncaceae. The organism belongs in the genus Soro- 
sphaera, and in its development closely resembles the classic example of this 
group, Plasmodiophora Brassicae Woronin. In the earliest stages observed, 
the parasite consists of small multinucleate amoebae in the root hairs and outer 
cortical cells of the infected plants. The roots show no hypertrophy, and 
scarcely any other outward sign of the presence of the parasite, which can 
discovered only by microscopic examination. In the vegetative stage all the 
nuclei of the amoebae divide simultaneously by the formation of a chromatic 
ring or plate surrounding an elongated karyosome. The process is identical 
with that described for Plasmodiophora Brassicae. At the beginning of spore- 
formation the protoplasm of the amoebae separates into a number of amoebulae, 
each with a single nucleus. The nuclei of the amoebulae undergo two divi- 
sions, forming four uninucleate spores. The spores remain loosely aggregated 
in sorospheres; their germination was not observed. The paper concludes 
with a brief description of Entorhiza cypericola, a member of the Ustilagineae 
mee the roots of various species of Juncus. 
S gives an account” of the development of Gnomonia erythrostoma, 
cells, resembling in this respect other ascomycetes except the mildews. 
first fruiting organs to appear are spermagonia, which are produced in great 
numbers on the lower surface of the leaves. The spermatia, which are dis- 
charged from the spermagonia in enormous numbers, are single-celled fila- 
mentous bodies with large nuclei and little cytoplasm. This structure, which 
BLackmaN has pointed out as characteristic of male cells, leads the author to 
regard the spermatia as abortive male cells. The perithecia originate, as in 
other ascomycetes, as interwoven masses of hyphae near the lower epidermis. 
Branches from some of the outer cells of the mass protrude through the stomata 
of the leaf and bear a superficial resemblance to trichogynes. No case of their 
functioning as such was observed, however, although it often happens that 
easily explicable when one considers the enormous number of spermatia pro- 
duced. That the projecting hyphae do not function as trichogynes is further 
2 Wotr, F. A., A leaf blight on the sau mistletoe, Phoradendron flavescens 
(Pursh) Nutt. Mycologia 2:241-244. pl. 3 10. 
3x ScHwartz, E. J., Parasitic root cu. of the Juncaceae. Annals of Botany 
24:511-522. pl. go. 1910 
22 Brooks, F. T., The development of Gnomonia erythrosioma Pers., the cherry 
leaf-scorch disease. Annals of Botany 24:585-605. pls. 48, 49. 1910. 
