Coker: Two New Species of Water Molds 
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diameter from 24 to 40 n averaging about 30 /a, the wall about 2 fi 
thick, not so nearly filling the oogonium as in P. cymosa; antheri- 
dia short-clavate, terminating a stalk that usually arises from im- 
mediately below the oogonium, but sometimes of more distant 
origin, or rarely diclinous, one, two or occasionally more on every 
oogonium and generally applied to its top or distal half, with an 
antheridial tube which reaches and apparently fertilizes the egg; 
resting bodies resembling sporangia or oogonia present in quan- 
tity, after a rest forming spores or germinating with tubes. 
The species is sharply separated from P. cymosa by the much 
larger and always smooth oogonia, larger eggs, larger sporangia, 
absence of strictly basal antheridia and presence of elongated 
forms of sporangia. Illustrations of the globular type of spo- 
rangia, which are the first to appear in clean and vigorous cultures 
are given in figures 1 and 2. They are of the same appearance as 
those of P. cymosa. The papilla is usually formed at the tip 
when growth is active, but if there is a rest it is as apt to be 
formed at any other point (figs. 2, 7, 10). Intermediate and 
elongated forms are shown in figs. 4 to 10. As in P. cymosa the 
internal pressure is dissipated before the last spores emerge and 
it is often many minutes before all find the exit. As shown in 
the figures, the papilla may be quite abrupt or may gradually taper 
into the body of the sporangium. 
The oogonia are often closely associated with the sporangia 
(figs. 2, 11 and 12), but the more common arrangement is a 
terminal oogonium on a rather short lateral branch as shown in 
fig. 13, with a single stalked antheridium arising from immediately 
below it. The antheridial branch almost invariably carries but a 
single antheridium, which is short, thick and densely filled with 
protoplasm. The antheridial tube is quite conspicuous and its 
behavior is such that there is scarcely any doubt that fertilization 
takes place. The protoplasm of the antheridium passes into the 
tube and soon after no protoplasm or tube can be seen, indicating 
the discharge of the former and collapse of the very thin-walled 
tube. The tubes are distinctly shown in figs. 11, 12 and 15. 
Oogonia with two eggs are not very rare. One of these with 
two antheridia is shown in fig. 14. Oogonia with four eggs were 
seen twice. One of these, of anomalous shape, is shown in fig. 16. 
The occurrence of more than one egg in the oogonium of P. 
