May, 1921] 
KAUFFMAN — ISOACHLYA 
four days old, under the same temperature conditions, showed the same 
general abundance of oogonial initials, but in this case the oogonial swellings 
occurred at the ends of stalks in pairs, in series of two, or with one on an 
adjacent short lateral stalk. After ten days the greater number of these 
had developed further, so that the terminal one possessed oospheres or 
oospores while the basal ones were initials and in many cases showed signs 
of never being able to complete their destiny. Later observations showed 
this surmise to have been correct, the apical ones maturing further, the 
contents of the basal ones breaking down. (See fig. 11, a-c.) 
In a 0.1 percent solution of leucin, under the same conditions, after four 
days only scattered and quite young oogonial initials were seen. After 
ten days they were abundant, and a large proportion contained oospheres. 
But in this case the globular oogonia were borne singly at the ends of long 
supporting hyphae, not more than i to 2 percent being in series of two. 
(See fig. 12, a-c.) 
In all the cultures mentioned, no antheridia were ever observed. The 
pits of the oogonial wall were always rather far apart, not large, and in 
leucin unusually distinct. The torulose habit of the oogonia is reduced as 
we go down this list of cultures. The presence or absence of some substance 
in the synthetic solutions is doubtless responsible for the inability of the 
development of the later oogonia to run its usual course. Although no 
combinations with mineral salts were extensively tried with the haemoglobin 
and leucin solutions, work on other species has shown that there is no 
reason to suppose that the disintegrating effects of the haemoglobin and 
leucin could not be offset by the addition of proper amounts of certain 
salts, the oospheres thus being induced to complete their development to 
maturity. It will be noted that the period of time necessary for the appear- 
ance of the reproductive organs is not strictly an inherent quality within 
the species, but depends, within limits, on certain other influences. The 
older investigations laid great stress on the exact period of time which any 
process, in the life history of a species, took to complete itself. In view of 
many indications in this and other groups of plants, this attitude needs to 
be much changed before we can lay a sound foundation for plant morphology. 
In records of cultures of the Saprolegniaceae it is still frequent to see flies, 
wasps, white of egg, this, that, and the other substratum mentioned without 
further details, as if the organism were assumed to act alike on all. 
" Saprolegnia monilifera de Bary" has, so far as I know, been observed 
and studied only by de Bary himself. He found it only in one lake, near 
the Black Forest, Germany, from which he obtained it repeatedly, but was 
never able to get it from any other of his collections made through many 
years. De Bary considered its nearest relative to be Saprolegnia torulosa 
of the "ferax'' group; but he placed it in a separate section which he called 
the monilifer'' group. Its anomalous position was thus clearly recognized 
by de Bary, and since this was the only case known to him in which both 
