128 UNIVERSITY OF WISCONSIN STUDIES 
the differences in the fermentation of lactose and saecharose as 
a distinguishing feature between the American and French or- 
ganisms since they say that not all their strains fermented 
saccharose. Meyer and Aird have shown conclusively the in- 
constancy in fermentative powers of not only many American 
strains but also of different French strains. They conclude 
it is impossible to differentiate sporotricha into two distinct 
species by means of the fermentation of carbohydrates. These 
results have been confirmed by the writer. Greco’s observa- 
tion on a South American strain does not agree with those of 
de Beurmann and Gougcrot on French strains. 
Specific serum and dermal tests are probably of limited 
value in differentiating these closely related organisms though 
they may furnish important data for the basis of a group 
relationship. So far as the results indicate they show no dif- 
ferences between the French and American strains. 
From the above analysis it would seem that the basis upon 
which French investigators differentiate the Sporotrichumn 
schenckiit and Sporotrichwn beurmanni is, to say the least, 
very inadequate. On account of the pleomorphism of this 
organism there is an excellent opportunity to take advantage 
of sight and unimportant differences in order to create new 
species. It is of course true that no two strains are eractly 
identical. De Beurmann and Gougerot noted that certain 
of their strains manifested fixed pleomorphic changes that 
made them appear identical with the original Sporotrichum 
schenchii. Yet they did not suggest that these strains be 
ealled Sporotrichum schenckti. Concerning these slight dif- 
ferences, especially in organisms of this type, it would seem 
that it would be wise to assume a conservative attitude and 
to refrain as much as possible from the use of new and un- 
necessary terms. 
The question arises in connection with an organism of this 
kind, as it arises so frequently in biology, what differences 
are sufficient to warrant the creation of a new variety or 
species? Where shall the line be drawn between varieties 
since no two cultures of sporotricha are absolutely identical 
in every dctail and strains are ever prone to these striking 
