Oct. 2, 1916 
Aspergillus niger Group 
3 
Table) I .—Comparative oxalic-acid production in strains of Aspergillus niger and related 
organisms grown in flasks of 50 c. c. each of Czapek’s solution containing 5 per cent 
of sugar 
[Acidity and oxalate radical expressed in cubic centimeters of Njio sodium hydroxid required to neutral¬ 
ize 50 c. c. of medium] 
Culture 
No. 
Name of source. 
7 days. 
10 days. 
14 days. 
18 days. 
Acidi¬ 
ty. 
Oxa¬ 
late. 
Acidi¬ 
ty. 
Oxa¬ 
late. 
Acidi¬ 
ty. 
Oxa¬ 
late. 
Acidi¬ 
ty. 
Oxa¬ 
late. 
142. 
2469-4. 
hi. 
3528.7. 
4020.33. 
4049 . 
2657. 
4050 . 
2766. 
2774 . 
3534b....... 
3547 - 354 b... 
2396. 
2580. 
4030.5. 
3534 C... 
3522.30. 
3534 a. 
4030-1. 
4030.4...... 
A. ficuum (?). 
Soil, Delaware. 
A . niger (Amsterdam).. 
Pittsburgh. 
Soil, Texas. 
Sardine paste. 
Soil, England. 
Chinese galls. 
Human ear. 
A. cinnamomeus . 
Soil, Kansas. 
Missouri. 
Pepper, Spain. 
Unknown. 
A . fuscus . 
A. violaceo-fuscus (?).,.. 
A. niger altipes . 
A . carbonarius . 
A . ochraceus . 
116.17 
97-57 
62.30 
103. 74 
62.30 
61.03 
29. 78 
50.16 
39*77 
52. 70 
72.10 
47.80 
46. 24 
81.11 
34 - 97 
85-23 
17-73 
31-74 
31-54 
1-57 
xi6.21 
48.76 
67.82 
48.57 
65-95 
36-43 
30.64 
28. 58 
29.88 
34 - 94 
63-71 
45-96 
31-01 
84.07 
11.96 
81.08 
9-15 
25-41 
14-57 
7.10 
142.85 
103.15 
80. 52 
97.96 
69.94 
69.30 
58.78 
54-36 
53-10 
52.41 
47.80 
So- 74 
45-55 
49-57 
28.60 
26. 64 
12-73 
II. 17 
5-58 
I.47 
155-82 
94-35 
94. 72 
79 - 9 S 
79-03 
59 - 41 
74 - 73 
51-00 
62.77 
56 .05 
61.47 
65. 20 
56.05 
63.90 
17 -Si 
40- 73 
18. 87 
23-54 
18.31 
13.08 
167.90 
in. 88 
79 - 54 
89.92 
67.80 
75 * 24 
29- 58 
51.12 
26.06 
37- 62 
28. 22 
58. 78 
33-90 
32.90 
13.90 
19 - 39 
9. 01 
9. 21 
6.66 
.78 
182.90 
96 . 59 
94-35 
85-56 
82. 87 
66. 5i 
45 - 59 
47. 64 
41.48 
46 - 71 
43-34 
74-92 
48.95 
48. 20 
15-32 
33-07 
I 7 - 56 
23-35 
21-33 
14. 70 
153* 21 
99*53 
71.12 
61.14 
80.72 
32 - 33 
22.92 
37-32 
14.69 
38. 20 
28. 80 
34- 68 
15*28 
33 - 50 
2 - 35 
12.34 
3*13 
8.03 
3 - 53 
•39 
170.01 
99.02 
87.05 
60.34 
94 * 53 
40-54 
39 * 42 
44.09 
30- 83 
49 - 70 
44*09 
54 - 93 
31 - 39 
49-66 
16.44 
28.02 
16.44 
23-54 
13*85 
xi. 58 
A study of Table I disposes effectually of the idea that because a 
species of Aspergillus is black or fuscous it must possess in specific measure 
the power to produce oxalic acid. It is noteworthy that all of the series 
possess this power in some degree and that some of the series show it in 
excessive degree. Others, however, produce this acid in no greater 
amounts than do members of other groups, as has been shown in the 
authors' previous paper. 1 These wide variations therefore indicate 
either a group of heterogeneous ancestry or a series of races of a single 
ancestry, which show great variation in the ability to produce a par¬ 
ticular reaction. If such variation can be correlated with morphological 
characters, it is a valuable accessory in the identification of species. 
If cultures exhibit only quantitative differences in the reactions selected 
for study, such differences may be exceedingly important economically 
without justifying the description of separate species. 
Nine forms representative of the range of variation found in Table I 
were selected for further experiment. No. 4047, growing upon strong 
lemon juice, was added. Tubes of Czapek’s solution agar, Raulin’s fluid, 
wort agar, and beef-peptone agar were prepared. Duplicate tubes of 
each of the four media were inoculated from a single tube of each of these 
10 strains. The cultures were incubated at 37 0 C., until ripe spores were 
abundant, which was usually in about three days. Then transfers were 
made to fresh tubes of the same medium. In this way in a period of 
about five weeks each strain was transferred seven times upon each of 
1 Currie, J. N. p and Thom, Charles. Op. cit. 
