1907] SHEAR & WOOD—ASCOGENOUS GLOEOSPORIA 263 
be successfully segregated as species upon the basis of morphological 
characters. Though we have examined a great deal of material, of both 
conidial and ascogenous stages, from various pure cultures, as well 
as from the natural hosts, we are unable to find any differences of 
sufficient constancy or importance to make it possible to distinguish 
species or even varieties except the host be considered. Miss STonE- 
MAN describes and figures most of her species as having perithecia 
with a distinct neck or beak. We have very rarely seen in any of our 
cultures as conspicuous a beak as she figures. In all other characters, 
however, the forms we have studied agree with hers. The conidia 
of these fungi are well known to be quite variable in size and shape, 
and it is frequently possible to find in a single acervulus conidia 
varying in length from 10 to 25 m and in thickness from 3.5 to 6 4, 
so that the range of variation in a single culture will usually cover the 
range of variation found in any of the forms we have studied. This 
is not only true of the conidia, but is also true of the ascogenous 
forms. The greatest variation found in the size of ascospores is 
from 9 to 24 # by 4.5 to 8 , the usual measurements being about 14 
to18 by 5 to6. In shape the asci vary somewhat, being usually 
sub-cylindrical or clavate. The ascospores vary but little in shape 
and appearance of contents. They are usually slightly curved or 
allantoid, having the contents in fresh specimens regularly granular, 
with a more or less distinct hyaline zone at the center, and when 
fully matured are of a light greenish-yellow color. This color, how- 
ever, is hardly noticeable except in mature specimens. From this it 
will be seen that these organisms cannot be satisfactorily distinguished 
by their morphological characters, so far as the conidia and asci are 
concerned. Some of the conidial forms have been separated hereto- 
fore upon the basis of the presence or abs¢ence of dark setae in the 
acervulus. This, as has been pointed out by other writers, is also an 
uncertain and variable character. We have found setae in the 
acervuli in one part of a pure culture, whereas in other parts of the 
same culture they were absent. We have also found this same 
variation in acervuli occurring upon leaves, i iota in the form 
found upon the cranberry. 
The question remains whether these organisms can or should be 
separated as physiological species. The answer depends upon 
