300 BOTANICAL GAZETTE [NOVEMBER 
various chemicals to this group of plants; for it was of course 
early learned that the data worked out for phanerogams by 
Kahlenberg and True (’96) and Heald (’96) were a contrast rather 
than a comparison when placed beside the facts learned by 
experiment from the fungi. Heald (’96) called attention to this 
fact on finding a fungus growing vigorously in a solution of HC 
that had killed the root of Pisum. The data obtained from the 
trial cultures proved invaluable in making up the regular cultures, 
as it was then possible in most cases to make up a seriesof 
twelve dilutions in no. 1 of which the spores would certainly be 
killed, while in no. 12 the fungus would be practically unharmed. 
In the regular work all cultures were made up in duplicate, 
including duplicate checks in pure beet infusion. Important 
points were quite frequently checked over in duplicate and some- 
times in quadruplicate. This was also done in the case of unés- 
pected developments; for instance, the writer was surprised 10 
find the spores of Penicillium showing so great a specific resist- 
ance to acetic acid. Repeated checking, however, proved the 
correctness of the first observation. 
One of the most marked features of the entire work was the 
regularity in results. It is true that the cultures nearest the 
inhibiting point in a few cases varied to the extent that gee 
nation of a number of spores took place in one culture wil 
the duplicate failed. Such were not considered evraitt. 8 
however, both cultures of a certain strength grew and one ee 
weaker concentration failed, the latter would be ern 
erratic. Such erratic cultures, however, did not exceed ae 
in a work requiring upwards of forty-five hundred pene 
tures aside from preliminary work. Such as did ee st 
doubtless due to oversight in cleaning the cells or other a¢ cay 
Examination of cultures, noting results, cc inter . 
made up in the early part of the day, and were examine ‘oui | | 
vals of from three to six hours for the fourteen hours “ spores be 
and at longer intervals until the fungus had matured, or cc 
in the cultures which had failed to germinate were fra tage f 
pure beet infusion to test their vitality. The perce = 
