406 BOTANICAL GAZETTE [DECEMBER 
would have prevented the germination of the spore had it been 
in contact with it. 
16. Peculiar knotted or twisted hyphe frequently result 
from the attempt to grow in a poisonous solution. 
17. A spore may be able to germinate and grow slightly in 
a solution but still be unable to attain full development. 
18. Potassium permanganate at certain strengths acts as a 
selective stain, differentiating uredo- from teleutospores of 
Uromyces caryophyllinus. 
19. Bread may be moistened with a solution which prevents 
germination of spores. This solution may evaporate and the 
spores can then grow. 
20. An occasional spore may germinate and grow perfectly 
normally in a solution which prevents hundreds of normal spores 
around it from germinating. 
21. Penicillium in a nutrient medium offers greater resistance 
to poisons than do any of the other fungi worked upon. 
22. Uromyces does not diminish in vigor of growth with the 
increased strength of the poison, but it does diminish in the 
percentage of spores which germinate. 
In conclusion I offer my most grateful thanks to Dr. B. D. 
Halsted for much kind assistance and advice as well as for pre- 
liminary training in former years; to Dr. W. A. Kellerman for 
his courtesy in extending to me the privileges of his physio- 
logical laboratory and also for material and advice; to Mr. E. 
M. Wilcox for many courtesies in the laboratory. 
THE UNIVERSITY oF CHICAGO. 
