286 
Mycologia 
by cymose branching beneath the old ones, but occasionally also 
by proliferation through the empty ones, exactly as in Saprolegnia. 
Spores formed in several rows as in Saprolegnia and Achlya, on 
emerging all ciliated, but varying greatly in behavior — some swim- 
ming away as a rule, others remaining attached to the tip of the 
sporangium ; oogonia produced on the tips of short lateral 
branches, usually near the base of the main hyphae, sometimes 
intercallary; their walls smooth and without pits, except for the 
thin places where the antheridia are attached; oospores usually 
two, often four and rarely one or eight; their diameter from 22 to 
37 jx, averaging about 30 /*; antheridia always present, generally 
several on each oogonium, short club-shaped and terminating slen- 
der branches of diclinous origin which show a decided tendency to 
twine about the oogonial branches ; antheridial tubes enter the 
oogonia, run among the eggs, and probably fertilize them. 
In fig. 1 the sporangia are shown in a group after the manner 
of Achlya. The bending of the sporangia that is quite noticeable 
in this figure is characteristic, though not always so pronounced. 
In figs. 2 and 3 are shown the proliferation of sporangia by 
both the Achlya and Saprolegnia methods on the same thread. 
The latter method is rare, but when it does occur is exactly as in 
Saprolegnia a condition that has not been observed in any other 
species of Achlya. In fact I know of no reference in the litera- 
ture to internal proliferation of any kind in Achlya except by 
Peterson 2 who says : “ Thus I have seen zoosporangia which had 
proliferated in undoubted species of Achlya .” 3 The behavior of 
the spores on emerging is remarkable and very variable. In re- 
gard to their action I shall give the following quotation from my 
notes made at the moment of observation: 
The spores emerge somewhat elongated and may be seen to bend backward 
at the ends and fuse into a pear-shaped spore, as is the case in Leptolegnia. 
The spores are very sluggish and most of them fall down immediately around 
the sporangium mouth and encyst, also a lot are often left in a group that 
sticks to the sporangium mouth, giving the effect of Achlya. 
1 find cases where all, or nearly all, of the spores group themselves at the 
mouth exactly as is typical for Achlya. When conditions are unfavorable the 
spores sometimes do not emerge at all and in such cases they sprout in position. 
Noticed two sporangia empty near together. In one the spores grouped 
themselves at the mouth of the sporangium just as in Achlya, except that a 
2 Ann. Mycologici 8: 520. 1910. 
3 The extreme rarity of such a phenomenon in Achlya would make it desir- 
able that such an observation be accompanied by figures. 
