Wilson: North American Peronosporales 
63 
infestans. The method of oospore formation in this and related 
species is unique among the Phycomycetes. 
In nature the fungus is known only from the peculiar pink-rot 
of potato tubers which it produces. On solid media like oat agar, 
potato stalks, bread, and carrots oospores but no conidia were 
produced, while the reverse was true in regard to liquid media. 
Conidia were produced most abundantly on a watery extract of 
peat soil. 
6. Phytophthora infestans (Mont.) De Bary 
The present species has been a storm center ever since its 
advent into the scientific world, while its trouble-making possi- 
bilities have not yet been exhausted. At first a battle royal waged 
in western Europe as to the proper name of the species which 
was then referred to the genus Botrytis. So vigorous was this 
warfare, and so loosely were citations given that anyone who will 
successfully unravel the tangle in such a way as to effectively and 
equitably safeguard the honors due each of the contestants, dis- 
posing of their claims in a strictly impartial and judicial manner, 
and arriving at a designation of the species which will meet the 
requirements of any recognized code of nomenclature, he will 
have qualified as a real “ nomenclatural expert.” 
The next violent discussion was precipitated by the announce- 
ment by Worthington G. Smith of the discovery of the oospores 
of the fungus. The results of the ensuing discussion were 
humorously summarized by Smith who wrote that “ the oospores 
became a kind of a political subject — oospores of P. infestans or 
not oospores of P. infestans ?” (Clinton, 1911b). More re- 
cently the publications of Clinton and of Jones for a time bid fair 
to add to the interrogation “ and if oospores, whose?” 
In America two names are conspicuously associated with the 
investigations of the morphology' of this fungus. The first note 
concerning what may now be regarded as probably progametes of 
this species appeared as an abstract (Jones & Giddings, 1909) of 
a paper which was not published in full. This was followed in 
less than a year by the announcement from the same laboratory 
(Jones, 1909) of the finding of oospore-like bodies of about 30 
diameter, but with no evidence of antheridia. These were prob- 
