1900] CURRENT LITERATURE 427 
into the Chloromonas cell, which eventually dies. The amount of protoplasm 
in the Rhizidiomyces increases rapidly, until the portion outside of the algal 
cell is almost as large as the host itself. This part then prepares to develop 
and discharge the swarm spores. The protoplasm is gathered from the 
interior, and a neck is formed through which the divided contents escape 
into the water as small uniciliate zoospores that swim slowly away.—B. M. 
Gopi” has investigated the life history of a new species of Pythium that 
lives in the dead and dying filaments of Vaucheria. Pythium tenue is a very 
delicate form whose hyphae can hardly be more than 1—3m in diameter. It 
grows in the interior of the Vaucheria filaments, sending an occasional free 
end of the mycelium through the wall of the alga to the exterior. The end 
of such a hypha becomes swollen, but is not cut off by a cross wall as is 
usually the case when sporangia are formed. However, the protoplasm in its 
interior develops several swarm spores which shortly escape. The swarm 
spores quickly germinate, coming to rest in the exterior of the Vaucheria 
filament, where each puts forth a germ tube that pierces the cell wall and 
within three hours may develop a long hypha. The sexual organs are small 
and chiefly interesting from the fact that the end of the antheridial filament 
is not cut off as a distinct cell. The oospore is 8-gu in diameter and 
possesses a smooth wall. Nothing is known of its cytoplasmic structure, and 
its germination has not been observed.—B. M. DAVIS. 
Mr. O. F. Cook has published in Sczence (12: 475-481. 1900) his very 
interesting paper on “The method of types in botanical nomenclature. 
After a well organized discussion of the subject, the following general state- 
ments are advanced. “In biology a species is a coherent or continugds 
group of organisms.” ‘For nomenclatorial purposes a species is a group 
of individuals which has been designated by a scientific (preferably a Latin 
adjective) name, the first individual to which the name was applied con- 
stituting the type of the species.” ‘‘ For purposes of reference and citation 
specific names which appeared previous to the Sfecies Plantarum ot Linnaens 
"are not regarded in botanical nomenclature.” “A genus cf lg vars : ve 
species without close affinities, or a group of mutually related species. 
generic name is established in taxonomy when it has been applied to a 
recognizable species.” “The generic taxonomy of plants may be treated as 
beginning with Tournefort’s /stitutiones (1700). —J _M.C. 
Mr. L. A. Boope has begun the publication of a series of papers oe 
parat j! hizaeaceae, an 
the comparative anatomy of the Hymenophyllaceae, Sc = gs 
Gleicheniaceae, the first 7 dealing with the Hymenophylleacez. 
*6Gonr: Entwickelungsgeschichte des Pythium tenue, nov. SP. Scriptis Bot. Horti 
Univ. Imp. Petropol. 15: 211. pls. 4-5. 1899. 
7 Annals of Botany 14: 455-496. Als. 25-27: 1900. 
