June 1, 1925 
H-ion Concentration and Pigment in Fusaria 
1015 
Table III.— Color of the pigment 
produced by different species of Fusa- 
riurn at different initial hydrogen-ion 
concentrations of dextrose-agar cultures, 
during a 10-day growth —Continued 
F. oiysporum var. 
resupinatvm Sher. 
Do. 
Do. 
Fusarium sp. (15J_ 
Do.. 
Do. 
Do. 
Do. 
F. angustum Sher_ 
Do. 
Do. 
Do... 
Do. 
F. loncheceras Sid.... 
Do___ 
Do. 
Do. 
Do.. 
Do.. 
F. momh/orme (Shel.) 
Sher. 
Do. 
F. radictcola Wr. 
F. martii Ap. et Wr. 
Color of pigment 
Shrimp, pale. 
Light vinaceous 
pink. 
Do. 
Shrimp pink. 
Do. 
Shrimp, pale. 
Light vinaceous 
pink. 
Do. 
Shrimp pink. 
Do. 
Ochraceous buff. 
Do. 
Pale ochraceous buff. 
Flesh pink. 
Pale rose purple. 
Shrimp pink. 
Ochraceous buff. 
Pale ochraceous buff. 
Hydrangia pink. 
Vinaceous pink. 
Purplish pink. 
Purple. 
Purplish blue. 
Hydrangia pink. 
La France pink. 
Vinaceous pink. 
Vinaceous purple. 
Lilac. 
4.0 I Scarlet. 
5.0 Peach red. 
6.0 Cinnamon purple. 
7.0 Greenish purple. 
7.5 Greenish blue. 
4.0 I Maroon red. 
5.0 1 Nopal red. 
6.0 Cinnamon purple. 
7.0 Greenish purple. 
7. 5 Greenish blue. 
Table IV.— Color of pigment present 
in 40-day-old cultures of Fusarium 
cromyophthoron, grown in dextrose 
solutions at different initial but non- 
adjusted hydrogen-ion concentrations, 
together with determinations of the 
initial and final Ph value of the dif¬ 
ferent cultures 
Hydrogen-ion con¬ 
centration of cul- 
turns 
Color of pigment 
Initial 
Final 
Ph 
Ph 
3.0... 
4.5 
Van Dyke red. 
4.0_ 
4.5 
Do. 
5.0_ 
5.6 
Orange pink. 
6.0_ 
7.0. 
5.8 
6.2 
Shrimp pink. 
Pale snnmp pink. 
7.5_ 
6.4 
Do. 
Table V.— Color of pigment present 
in 40-day-old cultures of Fusarium 
cromyophthoron, grown in onion decoc¬ 
tion at different initial but nonadjusted 
hydrogen-ion concentrations, together 
with determinations of the initial and 
final Ph values of the different 
cultures 
Hydrogen-ion con¬ 
centration of cul¬ 
tures 
Color of pigment 
Initial I 
Ph 1 
Final 
Pu 
4.0. 1 
5.6 
Van Dyke, red. 
4.7_ 
6.6 
Orange pink. 
5.4. 
6.6 
Flesh pink. 
5.8_ 
6.9 
Shrimp pink. 
6.2_ 
7.5 
Do. 
7.3_ 
7.4 
Pale shrimp pink. 
Table VI.— Color of pigment of sporo- 
dochia of Fusarium cromyophthoron, 
grown on various vegetable tissues 
EXPLANATION OF RESULTS 
The results given in Tables III, IV, 
V, and VI indicate that the initial 
hydrogen-ion concentration of the 
substratum, if not maintained con¬ 
stant by the addition of adjusting 
reagents, can not control the initiation 
or inhibition of pigment, because the 
reactions produced by the organism 
during the assimilation of nutrient sub¬ 
stances are capable of changing the 
initial reaction of the culture solution. 
Pigment was produced practically 
in every culture, regardless of the initial 
hydrogen-ion concentration. It be¬ 
comes evident, therefore, that the re¬ 
Vegetable tissues 
Color of pigment 
Solatium tuberosum L. 
(tuber). 
Allium cepa L. (bulb)... 
Phaseolus vulgaris L. 
(stems). 
Oryza sp. (grains). 
Melilotus alba L. (steins) 
Pale ochraceous huff to 
salmon. 
Pale ochraceous salmon. 
Pale ochraceous buff. 
Pale ochraceous salmon. 
Do. 
actions produced by organism or or¬ 
ganisms, which, in culture media more 
acid than the isometabolic point, de¬ 
creased the hydrogen-ion concentra. 
tion toward that of the isometabolic 
point, and in less acid culture media 
