214 COHN’s ‘‘ BEITRAGE ZUR BIOLOGIE DER PFLANZEN.” 
which act as haustoria if they happen to meet a Mastigothrix-thread. 
Obelidium mucronatum (gen. et sp. nov.), found in the empty case 0 
they themselves form the frandation of the new zoosporangium. 
dochytrium tenue (gen. et sp. nov.) grows in the tissues of cori Cala 
brane 
spindle-shaped enlargements ; these spindles often become divided by 
means of a transverse partition into two equal halves, in one of which 
all the saponins collects; it is this agreement half whith 
the zoosporangium, while the empty part remains as a sma 
bladder-like psd rape Sometimes, however, the future zoosporangium 
does not divid 
that the pee Rhizidium mycophilum pees a zoosporan: 
gium as an immediate consequence o ' germination 
cian iiber Organisation einiger Schwarmzellen. Von Dr. 
Ferd. Cohn. In this paper Dr. Cohn studies the structure of some 
Volvocinea, oa lly Gonium tetras, the species found by Alex. 
raun, and recently observed by Prot. Warming, and the structure of 
plasma the starch-nucleus is embedded. Division takes place first by 
means of a septum coinciding with the longitudinal axis of the cell 
and separating the starchnucleus into two equal portions, and then 
each of the new halves is divided by a septum at right-angles to the 
former one. Moreover all stages of this dividing process can be seen 
in a colony at the same time. “The growth was observed in the latter 
view 
protoplasm surrounded by a shell of starch which ha: 
from ies chioropayil of the cell. Similar starch-nuclei oceur in Hu- 
olvox, Palmellacee and Characiwm; and comparable 
i thiewe he accumulations of chlorophyll and starch surrounding 
the ices of the mother-cells of the spores of Zsoétes ard Anthoceros. 
he: © ells of Ci Pedi , Hyd and Ulothriz 
starch-nuclei are found ; these, "thon similar to 
ioned, differ from them by the fact tht they as 
