OLDENBUSCH: STIMULATION OF PLANTS 385 
TABLE III (con.) 
STERIGMATOCYSTIS NIGRA 
Exp. A 
No. of 
hours M/800 M/8,000 M/16,000 M/22,000 abe 000 M/40,000 Control 
29% = 44.5 _ $00 0.7 — 6.5 - 20. n 
48 126.2 Over 300 — rb 300 over300 224.9 
Exp. B 
I5 no no no no no 6.4 no 
20 no no no no no 75.6 no 
35 no no no no no over 300 no 
65 no — Over 300 over300 over300 “ “ start 
Exp. C 
19 no no no no 117.0 124.9 no 
25 no no no 137-5 oOver300 oOver300 no 
27 no no no over 300 * no 
68 no no no Pe ide tceeee no 
gI no no OEE COO Oe ae a a ee 
Exp. D 
19 no no 78.4 57-1 over 300 = =152.3 no 
25 no no Over 300 over300 ‘ ** over 300 no 
74 no no 4c sa “ee as ac oe ‘i “ee start 
weight of the germinating hyphae. In their experiments 150cc. 
Erlenmeyer flasks were used as culture bottles and, with pipettes 
and other apparatus, were cleansed with cleaning solution, rinsed 
in tap water a number of times, then in distilled water and finally 
in double distilled water. The same solution as in the former 
experiment, but without the gelatine and with double distilled 
water was employed as a culturemedium. ‘The trace of ferrous 
sulphate was introduced by adding one drop of a saturated 
solution of ferrous sulphate in double distilled water. 
After the nutrient solution was made up, it was inoculated 
in bulk with the Sterigmatocystis spores, and 50 cc. of the inocu- 
lated solution pipetted into each flask. The aqueous CS, 
solution (also prepared with double distilled water) was added 
last. The flasks were then corked by means of a mercury air 
trap, which would allow air to come into the flask, but would not 
allow any gas to escape from the flask and thus change the CS, 
ratio. 
