554 BULLETIN 347 
the Andersons (1912, a and b), and discussed under EF. gyrosa 
by Clinton (1912, a and b) as the “ narrowly-oval-spored 
Endothia ” 
3. E. gyrosa (Schw.) Fr., the bacilloid-spored southern form, which 
Shear (1912 b and 1913 a) had previously called E. radicalis 
(Schw.) and Clinton had discussed under the name of E. radicalis 
(Schw.) Farl., or the ‘‘ linear-spored Endothia ” 
The last of the three need not be considered especially at this time, 
since it has not been confused with the true canker fungus. Finding 
no intermediate forms between the first two, Shear and Stevens conclude 
that ‘unless such intergrading forms should be discovered later, there 
seems to be no way of escaping the conclusion that the two organisms 
are specifically distinct, according to the most conservative taxonomic 
standard of species prevailing at present in mycology.” 
In this publication the canker fungus will be referred to as Endothia 
parasitica. The complete synonymy is as follows: 
Endothia parasitica (Murr.) Anders. Phytopath. 2:210, 262. Decem- 
ber, 1912 
Diaporthe parasitica Murrill. Torreya6:189. 1906 
Valsonectria parasitica (Murr.) Rehm.. Ann. myc. 5:210. 1907. 
Ascom. exs., fasc. 39, nO. 1710 
Endothia gyrosa var. parasitica (Murr.) Clinton. Science 36:913. 
December, 1912 
Concerning the pycnidial stage of the fungus, it was first referred to 
the genus Cytospora by Patterson (Clinton 1909:879), and shortly after- 
ward by Clinton (1909) to the same genus. Since that time it has fre- 
quently been referred to in the literature under that name. Reasons 
for considering this disposition of it as incorrect will be given in the 
discussion of morphology and life history. In 1906 Saccardo (Ann. 
myc. 4:272) erected the genus Endothiella, based on the pycnidial form 
of Endothia gyrosa (E. radicalis [Schw.] de Not., according to Shear). 
Since the imperfect stages of our American Endothiae are practically 
indistinguishable, it is evident that the pycnidial form of E. parasitica 
should be referred to that genus, if there is ever any need of considering 
it apart from the perfect stage. 
History of the pathogen 
When the disease was first noticed in this country in 1904 it was a com- 
paratively simple matter to determine the association of the fungus with 
it. But where did this fungus come from, and why had it not been noticed 
before? There were only two possibilities: (1) either the fungus had 
always been here, but was now for the first time brought to notice; or 
