254 PovAH: A CRITICAL STUDY OF 
thoroughly dried out, in the course of which process the medium 
and fungus had contracted and shrunk away from the glass. 
Thus it was a simple matter to remove them intact. Each speci- 
men was einen to the bottom of a cardboard box, measuring 
41 x 3}.x 11 inches, the cover of which was fitted with a celluloid 
“‘window"’ 3% inches long and 2} inches wide. It is believed 
that with careful handling specimens prepared in this way will 
retain their characters for a long time. This opinion is not 
without evidence to support it, as the writer has examined some 
of his specimens which had been kept dry for one and one half 
years and also Ellis & Everhart’s North American Fungi, Nos. 
2454 and 972. In all cases the material was in such condition 
that its identity could be determined with certainty. 
IV. EXPERIMENTAL 
The experimental work was undertaken in the hope that the 
results, supplemented by the morphological characters, might form 
a basis for the separation of species. It was desired to know 
whether forms morphologically similar would react similarly to 
the same cultural conditions, and whether forms whose morphology 
might lead us to believe them distinct might exhibit, or manifest, 
their close affinity in their cultural characteristics under the same 
conditions. Such has been found true only to a certain degree, but 
the results of the experiments are believed to be of value in the 
taxonomic part of this study. Consequently, experimental data 
have been freely used in the commentary on the individual species. 
A uniform system of tabulation has been used throughout the 
series of experiments, in order to admit of easy comparison and 
also to avoid unnecessary confusion. The numbers given in the first 
column of TABLE I are used in all succeeding tables and through- 
out the work in the same way. It will be noticed in TaBues II 
and III that for each Mucor number there are two columns, the 
first containing Arabic, and the second Roman numerals. The 
former gives the height (length of sporangiophores) in millimeters, 
the latter the growth (judged by mass appearance), IV being 
excellent, III good, II fair, and I poor. It should be added that 
the presentation of results has been condensed on account of 
lack of space; hence, in the case of each medium, only the maxi- 
