390 BOTANICAL GAZETTE | DECEMBER 
remarkable vigor, producing a tube fully twice the usual length, 
while in two other cultures of the same strength respectively 
one in 100 and two in 200 grew. The fatal strength here is thus 
evidently #,, while ;%, has an appreciable toxic action, and yy 
is strongly toxic. 
TABLE XIII. 
POTASSIUM BICHROMATE. 
Botrytis Macrosporium Penicillium Uromyces 
Grew Failed Grew Failed Grew Failed Grew Failed 
ao | 2 | 3 8 | 9 acM 9) eee 
1280 3200 1280 3 1600 3200 1280 
Ua n n n 
- 640 2 640 - 800 3 640 t : 640 
ra n - 
2 2 ee 
aoe : 320 : 160 320 
nt n n as 
2 
* 160 - 160 2 Io 160 
n n n 
2 2 
40 - 40 40 
: n 
n n irene 
- Io @ ae 4 ro 
Bare 
* No. 715. - Grew poorly. 
{ Nos. 712, 713. One in seventy-five grew normally. 
No. 634. Two spores grew well.—No. 635. One in eighty grew.—No. 636 
Three in seventy-five grew. é 
Potassium bichromate —This would not allow the germination 
of Botrytis spores when of ;,,5 strength. No weaker was tried. 
Macrosporium would not grow in yore) and in the next weaker 
tried, 5/5, it grew poorly. Penicillium failed to grow in ye00 
and weaker were not tried. Uromyces spores were nearly all 
killed by ,%,, would not grow in stronger, and were injured by 
even weaker. Penicillium grew in as strong as double normal, 
and killing strength was not reached. Uromyces was prevente 
almost completely by #, and stronger solutions absolutely pro- 
hibited germination. Weak solutions, such as z350) seemed to 
stimulate the early growth somewhat. 
