Jan. io, 1914 
Some Diseases of Pecans 
321 
After carrying in culture for about two months, a few spores were noted 
which were 1-celled, oblong, and slightly smaller than the typical asco- 
spores. These conidia as first noted were borne hyphomycetously, but 
later were found developing from dense groups of modified fungous cells 
like an acervulus and in size and shape resembling a typical Gloeosporium. 
For some time it was thought that this was a contamination, though no 
possibility of such an occurrence could be found. However, in order to 
determine this point with certainty, single-spore cultures were started 
from the 2-celled ascospores and also from the conidia, each individual 
spore being isolated and its germination carefully followed microscopi¬ 
cally. The resulting two series of cultures were similar macroscopically, 
and both soon developed typical perithecia and ascospores, and also the 
Gloeosporium conidia. This procedure was repeated 30 or 40 times with 
a like result in all cases. In several instances the germinating ascospores 
had within 24 to 48 hours developed mycelial threads which were cutting 
off conidia in considerable numbers, and in these cases the hyphal con¬ 
nection could frequently be traced from the parent ascospore to the 
conidium. 
However, it was noted after eight or nine months' growth in culture 
that the 2-celled ascospores were becoming fewer in proportion to the 
1-celled, and this tendency has continued until now, after more than two 
years in culture, the majority of the ascospores are 1-celled, though still 
of the original form and size. 
The possibility suggested itself that perhaps many of the apparent 
septa were in reality merely a denser layer of cytoplasm across the center 
of the single cell and that after many generations of growth in culture this 
cytoplasm had for some reason become more homogeneous. Whatever 
the explanation, the fact remains that in these original strains a change 
has taken place from a majority production of apparently 2-celled to 
that of 1 -celled ascospores and that the production of acervuli has become 
quite as abundant as that of the perithecia. It should be added, how¬ 
ever, that many of the ascospores possessed an undoubted septum, as 
clearly brought out by staining. 
During the last two years 10 or 12 other strains of the fungus have been 
obtained from both conidia and ascospores developed on naturally 
infected leaves and nuts. In these cases most of the ascospores have 
been unicellular, though a few have been found with a cross partition 
clearly brought out by staining. 
Inoculations 
Several series of inoculation tests have been carried out on the leaves, 
but on account of the exigencies of field travel and the difficulty of obtain¬ 
ing suitable material and conditions only two sets of infection experiments 
have been tried on the nuts. 
