468 
sitivity to various concentrations of mer- 
curic chloride in the culture medium. 
A graded series of concentrations of 
mercuric chloride of 1:1,000 to 1:25,000 
was prepared in a manner similar to that 
used in the tests with copper salts. Results 
of the test are shown in table 8. Because 
none of the isolates grew in concentrations 
of 1:1,000 to 1:10,000, only the dilutions 
of 1:10,000 and above are shown in table 8. 
As in the tests with aniline dyes and 
copper salts, the isolates varied considera- 
bly in their sensitivity to mercuric chlo- 
ride. One noticeable difference between 
I_tinors NATURAL History SURVEY BULLETIN 
Vol. 26, Art.6 — 
the reactions to mercuric chloride and the 
reactions to the other growth-inhibiting — 
substances was observed. In the various 
concentrations of aniline dyes and copper 
salts, size of the colonies of Fusarium in- 
creased as the dilution became greater. Al- 
though this reaction occurred to some ex- 
tent with mercuric chloride, it was not so 
pronounced. In most cases, if growth oc- 
curred at all it was very vigorous and cov- | 
ered the maximum space available in the 
Petri dish. In tables 3, 4, 5, 6, 7, and 8, 
white mycelium and maximum growth are © 
designated by 15, as derived from the 
Table 9.—Color reactions of isolates of the gladiolus Fusarium on steamed rice. Colors 
are from the manual of Ridgway (1912). 
ISOLATE 
After 3 Weeks 
45-73 Thulite Pink 
AS BOET Tee de % Dahlia Carmine 
46-3. White 
46-5. Indian Lake 
B69 oi eee Tee Spinel Red 
MLAS eh Ot 50k Thulite Pink to Dull Dusky Purple 
ti e a ee Spinel Red 
79 BN it ello pl ae Indian Lake 
ae Pes ee Spinel Red to Indian Lake 
AQ AS Mt Gee oy, Indian Lake 
49-23. Indian Lake 
49-30.. Indian Lake to Dull Dusky Purple 
49-31.. Spinel Pink 
50-6. Spinel Red to Indian Lake 
50-24 Salmon Buff, Thulite Pink, and 
Indian Lake 
50-27 Thulite Pink to Dark Maroon Purple 
UE eran te Conc Indian Lake 
Ta eee Spinel Red to Indian Lake 
Be (AS ees ks Thulite Pink to Indian Lake 
45-75.. Indian Lake 
45-78 Indian Lake to Bordeaux 
46-4. Spinel Pink to Spinel Red 
46-12 ...| Dahlia Carmine 
47-1 .| Thulite Pink 
47-8 Light Buff 
47-12 Thulite Pink 
ATAQE els oe a2 Thulite Pink to Indian Lake 
47-32 Spinel Pink 
49-1. Thulite Pink to Indian Lake 
vs JR | Le a ee Indian Lake 
A EW aan Sok eee Light Buff 
50-7. Thulite Pink to Indian Lake 
50-22 Thulite Pink 
50-25 Dull Violet Black 
47-2. Spinel Pink to Indian Lake 
47-3. Thulite Pink 
49-8. Indian Lake to Dull Violet Black 
BONIS, FS ee Cameo Pink 
50-23 Indian Lake to Dull Violet Black 
50-26 Thulite Pink to Indian Lake 
CoLor oF SUBSTRATUM 
After 11 Weeks 
Pale Purplish Gray to Deep Purplish Gray 
Bluish Black and Tawny Olive ; 
Tawny Olive 
Dull Violet Black and Tawny Olive 
Dull Violet Black and Tawny Olive 
Dull Violet Black and Tawny Olive 
Dull Violet Black 
Bluish Black and Tawny Olive 
Tawny Olive and Bluish Black 
Bluish Black to Tawny Olive 
Tawny Olive and Bluish Black 
Dull Violet Black 
Purplish Gray and Tawny Olive 
Bluish Black 
Purplish Gray and Tawny Olive 
Payne’s Gray to Bluish Black 
Dull Violet Black 
Dull Violet Black 
Tawny Olive to Dresden Brown 
Blackish Violet Gray and Bluish Slate 
Black 
Dark Violet Gray 
Plumbago Slate and Old Gold 
Dusky Slate Blue 
Tawny Olive and Plumbago Slate 
Clay Color to Saccardo’s Amber 
Deep Plumbago Gray and Tawny Olive 
Tawny Olive and Dusky Purplish Gray 
Dull Violet Black 
Sudan Brown and Deep Purplish Gray 
Dull Purplish Black 
Old Gold 
Dull Purplish Black and Dusky Slate Blue 
Plumbago Slate and Old Gold 
Plumbago Slate 
Dull Violet Black and Dusky Slate Blue 
Plumbago Slate and Old Gold 
Dull Violet Black and Dusky Slate Blue 
Raw Sienna 
Dusky Slate Blue 
Plumbago Slate 
