Jan., I92i] WANN — FIXATION OF FREE NITROGEN 15 
2 A. Same medium, with i percent glucose 
- 
I 
I 
2 
2 
5 
5 
6 
6 
Check 
Check 
Check 
Chlorella vulgaris Beyr. 
Stichococcus sp. 
Chlorella (?) sp. 
Scenedesmus (?) sp. 
Ster. 
Ster. 
Ster. 
+ + + + + 
+ + + + + 
+ + + + + 
+ + + + + 
+ + + + + 
+ + + + + 
+ + + + + 
+ + + + + 
27.260 
Lost 
27.773 
26.924 
26.941 
27.277 
26.888 
26.959 
26.393 
26.835 
27.154 
IzL7 0^ 
147.70 
147.95 
146.95 
146.70 
146.80 
146.90 
147.25 
147.20 
147.40 
147.80 
18 s^8 1 
18.772 J 
18.322 ) 
18.365 J 
18.581 1 
18.304 1 
18.308 1 
17.930 J 
18.205 \ 
18.372 J 
' 18.655 
> 18.344 
> 18.443 
^ 18. 119 
> 18.289 
-O.3II 
— 0.212 
-0.536 
-0.366 
Average all cultures 
18.299 
-0.356 
Tables 3 and 3A. Results of analyses of mineral nutrient agar cultures of green algae. 
Experiment of igiy-i8. Growth period, 226 days. Nitrogen source, ammonium sulphate 
3. Medium without glucose 
Culture 
Growth 
Total Mg. 
N Found 
Wt. of 
Medium, 
Grams 
Mg. N per 
100 Gr. Average 
Medium 
Mg. Loss 
or Gain, 
100 Gr. 
No. 
Species 
I 
I 
2 
2 
5 
5 
6 
6 
Check 
Check 
Chlorella vulgaris 
Beyr. 
Stichococcus sp. 
Chlorella (?) sp. 
Scenedesmus (?) sp. 
Ster. 
Ster. 
+ + + 
+ + + 
+ + 
+ + 
+ + 
+ + +* 
+ + + 
+ + + 
29.842 
30.338 
29.719 
29.701 
30.055 
30.090 
30.055 
30.691 
30.090 
30.284 
146.75 
147.65 
145.50 
145.95 
145.80 
146.30 
147.00 
147.05 
147.20 
147.40 
20.335 ^ 
20.547 J 
20.425 1 
20.350 1 
20.614 1 
20.567 1 
20.445 1 
20.871 1 
20.441 1 
20.546 J 
' 20.441 
^20.388 
\ 20.591 
> 20.658 
> 20.494 
-0.053 
+ 0.150 
+ 0.217 
+ 0.053 
} Average all cul- 
1 tures 
20.533 
+0.092 
3A. Same medium, with i percent glucose 
Check 
Ster. 
29.400 
147.10 
19.986 ^ 
Check 
Ster. 
29.233 
148.05 
19.739 
19.957 
Check 
Ster. 
29.825 
148.05 
20.145 
I 
Chlorella vulgaris 
(+ + + +)t 
28.834 
146.75 
19.648 1 
' 19.657 
— 0.300 
I 
Beyr. 
( + + + +) 
28.869 
146.80 
19.666 1 
2 
Stichococcus sp. 
( + + + +) 
29.365 
146.85 
19.996 1 
> 19.836 
— 0.121 
2 
( + + + +) 
28.923 
147.00 
19.675 J 
5 
Chlorella (?) sp. 
++++++ 
29.188 
147.35 
19.809 1 
> 19.776 
-0.181 
5 
++++++ 
29.082 
147.30 
19.743 J 
6 
Scenedesmus (?) sp. 
( + + +) 
28.746 
147.75 
19.456 
■ 19.261 
—0.696 
6 
( + + +) 
28.180 
147.80 
19.066 J 
Average all cul- 
tures 
19.634 
-0.323 
t Plus signs enclosed in parentheses indicate that the culture was dead at the time 
of analysis. 
