64 
Mycologia 
ably chlamydospores. A little more than a year elapsed before 
the announcement by Clinton (1911a) that “absolutely perfect 
oogonia, antheridia and even oospores have been obtained.” 
In the more detailed account of the discovery which appeared 
in a few weeks (1911b) the various steps in the development 
of the oospore are not so carefully described as were those 
of P. Phaseoli, yet the descriptions of the two species are 
quite similar. The illustrations which are reproduced from 
photographs also bear out this statement as some of them show 
the basal antheridium pierced by the oogonium. While no one 
has observed an aotual fertilization to take place in species of this 
genius Clinton notes that in case no antheridium were present the 
development of the oogonium would not pass beyond the differ- 
entiation of the oosphere. This certainly precludes the suggestion 
that the peculiar antheridia of this and other species ot Phytoph- 
thora are functionless. The oogonia at maturity are 34-50 /a in 
diameter, with a thick, reddish-brown wall. The oospores have a 
medium thick wall which is smooth and hyaline. They measure 
24-35 P ' n diameter. The experiments which were conducted to 
determine the faotors which govern oospore formation do not 
appear to have shed any considerable light on the subject. 
The final report of the investigations of Jones and his associates 
(Jones, Giddings & Lutman, 1912) appeared soon after these 
papers by Clinton. This paper is a valuable contribution to our 
knowledge of P. infestans in all its aspects. His discussion of the 
bodies which he terms “ resting spores ” differs widely from the 
account given by Clinton. The bodies which are described by 
Jones are produced in masses large enough to be barely visible to 
the unaided eye on account of their brown color. “ Much varia- 
tion in structure, grooping, and mode of development of these 
bodies has been observed, partly due to variations in medium. 
Most of these bodies have clearly been abnormal developments, or 
at least have failed to reach normal maturity. Indeed, we doubt 
if any of them are to be regarded as strictly normal. Neverthe- 
less, it seems worth while to figure and describe the more common 
or striking features observed” (p. 61). Figures 1 to 20 represent 
various bodies found in the earlier cultures. These are borne on 
enlarged hvphae and enclosed in what are interpreted as ex- 
