376 The Botanical Gazette. 
with two lateral cilia, and yet introduces Hesse’s figure of — 
P. DeBaryanum with oval uniciliate zoospores. 
According to Pringsheim,® P. entophytum has unicil 
zoospores. P. cystostphon Lindstedt (Cystosiphon pythiod 
R. & C.), according to Roze and Cornu’, has reniform sw. 
spores, the two cilia arising from the pointed ends instead ad 
from the side. P. Eguiseti Sadebeck,? which DeBary* places 
as a synonym of P. DeBaryanum, has swarm spores exactly 
like those of P. cystosiphon. P. DeBaryanum Hesse, as 
cated above, has, according to its author, oval uniciliate swarm 
spores. io 
The Pythium which I have studied from the botanical con 
servatories of Cornell University is what I have supposed to 
be the P. DeBaryanum Hesse, and is probably what usually 
passes for that fungus in America. The peculiarities which 
I have observed are as follows: The swarm spores in proce 
of formation are reniform with rounded ends, the developing | 
cilia issuing from the broadly rounded ends, which beca 
of the form of the body are turned to one side. Ont ' 
from the swarm-sporangium they are long reniform W 
pointed ends and a cilium is attached to each end di ee 
the point. After swarming for a while amoeboid movetl 
Lipemee <a ae 
uficiliate swarm spores. These swarm again an o 
come to rest and germinate. The questions arise = 
ing to the character of the zoospores, OF whet ua 
first biciliate, becoming later uniciliate, or whet! ie tae 
great variation in the different species in this bi 
at one time both kinds of zoospores will be devel 
another time only one kind. These ques 
attempt at this time to answer. 
tions I 
In studying the germination of the spores Zs ie ; 
Ceratiomyxa Schreeter® (Ceratium A. et S.), 4 © 
a r les page ae 
; . Bot. V. 1: 7 2 ae 
et des Péronosporées. go d. Sci. Nat. Bo’ trage z. Biologie © 
121. 1875, : : 1881 
®Zur Kenntniss der Peronosporeen. Bot. Zeit. se ae 
®*Engler u. Prantl’s Natiirlich. Pflanzenfam. 1: 1°. 
