1995] BRIEKER ARTICLES 229 
silt there were in a scil, the less time it was before the uredospores broke 
through the epidermis after an inoculation had been made. 
4. Those soils that were favorable for the development of the host 
were also favorable for the development of the rust; namely those contain- 
ing the most organic matter combined with silt and clay and a small 
amount of sand—soils with a high water retentivity, soils rich in nitrogen. 
If then the conditions favorable for bringing about distribution and 
infection were the same for the different soils, the rust should in time be 
more abundant on those plants grown in a heavy loam where the period of 
incubation of the rust was least, than on those grown in a light sandy soil, 
agreeing with the observations made by Roserts (I. ¢.) on the wheat rust, 
rather than those made by SToNE and Smrra (i. c.) on the asparagus rust. 
There is a possibility that while the asparagus rust may not have devel- 
oped so rapidly on the asparagus grown in light soils with a low water 
tetentivity, the greater abundance was due to conditions which were more 
favorable for bringing about infection. Whether the humidity is greater 
over sandy soils than over a heavy loam, the writer cannot say from per- 
sonal observations. Perhaps some one has already determined this factor, 
which is so important in bringing about the infection of cultivated crops 
with various parasitic fungii—Joun L. SHELDON, Agricultural Experiment 
Station, Morgantown, W. Va. 
