Apr. a8,1933 Spectes of Fusatium Isolated from Potato Tubers 
355 
The cultures may be kept in a normal condition for 12 weeks or more 
by keeping them at a temperature of 10® C. or less. 
Were the standardization work suggested on page 3S6 to be at¬ 
tempted, we would suggest as the media to be tested out a hard oat 
agar, potato stems, potato plugs, and possibly potato glucose agar. It 
would be advisable to try several regulated temperatures, together with 
a room temperature, the limits of which should be given, probably 12® 
to 25® C. Tests should be made to determine that time nearest which 
all llie species reach the normal stage of their growth, and if possible 
some method should be devised to standardize moisture and humidity 
conditions. 
PIirFAI.I.S IN IDENTIFICATION WORK WITH SPECIES OF FUSARIUM 
The greatest obstacle in the way of accurate determination of species 
of Fusarium is the lack of a good monograph of the genus, and this lack is 
due in part to nonstandardization of 3 ie methods used in identification 
work, especially as regards kinds of media, environmental conditions, 
and the relative value ascribed to various characteristics of the fun^s 
when grown in pure culture under laboratory conditions. The species 
and varieties intergrade and the differential characters used in the keys 
are not sufficiently distinct to permit any but an experienced investigator 
to use the key. To become an authority one must work long enough 
and with large enough numbers of species so that he can create within 
himself a conception of the species. In other words, he judges to what 
species the fungus in question belongs rather than actually identifying it. 
Pathologists in various parts of the world often in connection with 
some pathological studies isolate a species of Fusarium. In their eag^- 
ness to name the organism which is causing economic loss they describe 
it so incomprehensively that future workers are not able to identify their 
cultures with it and therefore more new names appear. 
Appel and Wollenweber (2) made a good beginning toward a monograph, 
but it was merely a beginning. Sherbakoff (18) has helped the situation 
somewhat with his ‘‘Fusaria of Potatoes,” but his key is deserving oi the 
criticism given above. He has split species up into so many varieties 
that to identify a specimen beyond its section becomes a tedious task of 
scientific guessing. 
In the near future the botanical world, especially the mycological world, 
must determine and actively promote some policy with regard to trino¬ 
mial nomenclature. If all the flowering plants were split into varieties 
on as many minor characters as are the fungi, binomial nomenclatiure 
would before long be a thing of the past. The American Code of Botan¬ 
ical Nomenclature (j) states in regard to categories of classification that 
the terms “subspecies” and “subgenus,” etc., may be used when addi¬ 
tional categories are necessary for the convenience in presentation of 
relationships, but “the term variety is relegated to horticultural usage.” 
The mycologist's difficulty arises largely from lack of perspective. 
The person who has worked on a single group for some time sees very 
real, fine distinctions which would not be at all significant to other 
mycologists. These distinctions may not be of enough importance to 
justify his making a new species, but they are too real to him to be 
overlooked, and he therefore originates a variety. Would it not be 
better to keep in mind that a species must have more or less flexible 
boundaries due to evolution which has taken and is now taking place, 
