174 BULLETIN OF THE BUREAU OF FISHERIES 
Table 9. — Relative abundance in the different ponds of the C series in 1928 of the principal algse in 
the centrifuge plankton 
Pond 
Organism 
June 27 
July 7 
July 19 
July 28 
July 30 
Aug. 9 
Aug. 20 
Aug. 30 
C 1 
Scenedesmus 
4, 500 
180, 000 
1, 260, 000 
123, 000 
7, 200 
39, 060 
1. 843, 200 
2, 430, 400 
337, 500 
63,000 
7, 680, 000 
5, 568, 000 
3,176, 880 
78,000 
1, 800, 000 
8, 032, 000 
1,236,900 
210, 000 
C 2 
8, 550, 000 
3, 840, 000 
546, 840 
C 3 
780. 000 
3. 000 
9.000 
2, 999, 600 
528. 000 
0,000 
313, 735 
12, 000 
63i 000 
3, 000 
C 4 
C 1 
Chroococcus, single 
cells .... 
C 2 
1, 140,000 
17, 920, 000 
13, 500 
342, 000 
48, 000 
2, 252, 460 
9, 000 
1, 178,310 
126, 000 
30, 000 
13, 888, 300 
126, 000 
C 3 
4, 230, 000 
120, 000 
22, 500 
C 4 
66, 000 
C 1 
Chroococcus, colony.. 
C 2 
195, 300 
54, 000 
572, 880 
3, 333, 120 
9,000 
9, 728, 000 
429, 660 
C 3 
234, 360 
C 1 
Aphsizomenon 
14, 000 
205, 500, 000 
48, 000, 000 
9, 000 
11,160, 000 
252, 000 
24, 000 
9, 000 
58, 320, 000 
C 2 
40, 200, 000 
868, 050 
C 3 
101, 700, 000 
264, 000 
31, 500 
90,000 
693, 000 
1, 368, 000 
6, 000 
563, 200 
729, 120 
126, 000 
9,000 
960, 000 
C 4 
C 1 
Oocystis, single cells,. _ 
30, 000 
21,600 
18,000 
91, 140 
3, 000 
93, 600 
91,140 
36, 000 
12, 000 
1, 920, 000 
720, 000 
1, 219, 720 
24,000 
C 2 
240, 000 
48, 000 
442, 680 
72, 000 
3, 000 
C 3 
C 4 
24, 000 
C 1 
Oocystis, colony. 
C 2 
840, 000 
C 3 
234, 360 
9, 000 
C 4 
12, 000 
3, 000 
C 1 
Pleodorina 
900, 000 
24, 000 
115,200 
216,000 
748, 800 
C 1 
Pandorina 
4,500 
756, 000 
C 1 
14, 400 
540, 000 
7, 040, 000 
6,400 
C 2 
450, 000 
540, 000 
48, 000 
C 3 
18, 000 
C 4 
3, 000 
1 
1 
Note.— O n July 28 no samples were taken from C 2, C 3, and C 4. 
Table 10. — Data on carbon dioxide, dissolved oxygen, chloride, phosphorus, nitrogen, and organic 
matter in milligrams per liter in 1927. Temperatures in degrees centigrade, turbidity in inches, net 
plankton in cubic centimeters per 10 liters of water. Also pH values 
POND D 4 
Date 
Tem- 
pera- 
ture 
Turbid- 
ity 
Oj 
pH 
C0 2 
free 
Chlo- 
ride 
Phosphorus 
Nitrogen 
Or- 
ganic 
matter 
Net 
plank- 
ton 
Total 
Dis- 
solved 
Or- 
ganic 
NH 3 
NOj 
NOj 
Or- 
ganic 
May 9 
17.2 
29 
7. 42 
8.4 
-15. 18 
3.0 
0.085 
Nil. 
0.085 
0. 032 
0. 120 
Nil. 
0. 632 
3. 83 
0.10 
May 19 .. _ 
13.3 
30 
6. 59 
8.5 
-6.08 
2.0 
.095 
0. 030 
.092 
.025 
.050 
Nil. 
.602 
3. 32 
.04 
May 29 
13.3 
38 
9. 18 
8.8 
-9. 10 
3.0 
.027 
.008 
.019 
.016 
.050 
Nil. 
.880 
2 16 
. 10 
June 9 . 
22.2 
46 
9. 55 
9.4 
-14. 16 
2.0 
.095 
Trace. 
.095 
. 128 
.035 
Nil. 
.720 
1.39 
.45 
June 20 . 
24.4 
41 
10. 46 
9.5 
-40. 44 
3.0 
.023 
.018 
.005 
.052 
.030 
Nil. 
.768 
2.68 
.12 
June 30 . . 
26.7 
48 
7. 22 
9.6 
-46. 52 
2.0 
.095 
.043 
.052 
.052 
.030 
Nil. 
.664 
1.65 
.28 
July 10 
23.9 
28 
7. 05 
9.7 
-40. 44 
2.5 
. 295 
.038 
.257 
.032 
.030 
Nil. 
.856 
2.21 
.16 
July 20 
21.7 
32 
5. 37 
9.0 
-28. 32 
3.3 
. 195 
.018 
. 177 
.024 
.050 
Nil. 
.912 
2. 17 
.50 
Tnly 
26 7 
29 
5. 50 
-18. 20 
3.3 
.043 
.064 
.030 
Nil. 
1.024 
1. 49 
. 10 
Aug. 8. .. 
25.0 
24 
3. 43 
9. 1 
-10. 10 
3.3 
.135 
.038 
.097 
.032 
.040 
Nil. 
1.024 
2.39 
.12 
Aug. 18. 
18.2 
28 
2.86 
7.6 
12. 64 
3.3 
.078 
.058 
.020 
.020 
.030 
Nil. 
1.600 
2.88 
.15 
Aug. 29.. 
21.7 
30 
5. 19 
7.8 
6. 56 
2.5 
.068 
.018 
.050 
.044 
.010 
Nil. 
.880 
1. 81 
.20 
Sept. 8 
23.3 
24 
4. 70 
7. 7 
5. 56 
1.8 
. 115 
.028 
.087 
.032 
.042 
Nil. 
1.080 
2.22 
.10 
Sept. 19 . . 
16.7 
24 
5. 86 
7.7 
5. 16 
2.0 
.073 
.038 
.035 
.036 
.017 
Nil. 
.960 
2.83 
.05 
Sept. 29 
11. 1 
27 
8. 21 
8.0 
10. 10 
3.5 
.073 
.030 
.043 
.036 
.047 
0.002 
1.260 
3. 07 
.30 
.041 
.033 
.924 
2.41 
. 18 
i . 
POND D 5 
17. 22 
41 
7. 79 
8.2 
2.12 
3.0 
0.048 
Nil. 
0. 048 
0. 038 
0. 120 
Nil. 
0. 632 
4. 24 
0.20 
13.3 
48 
6. 49 
8.2 
2. 02 
2.0 
.067 
Trace. 
.067 
.060 
.070 
0. 002 
. 601 
3. 33 
.05 
13.9 
60 
6. 23 
8.0 
6.59 
3.0 
.039 
0. 003 
.036 
.080 
.050 
Nil. 
.720 
1.31 
.25 
22 8 
46 
6. 31 
8.0 
4. 04 
3.0 
.086 
Nil. 
.086 
.048 
Nil. 
1.24 
. 15 
24 4 
50 
7. 84 
8.0 
8. 08 
2.0 
Nil. 
.048 
.040 
Nil. 
.528 
1. 10 
.09 
27.8 
53 
6. 05 
8.2 
5. 05 
2.0 
.095 
Trace. 
.095 
.032 
.025 
Nil. 
.600 
.83 
.06 
Tnlv 10 
24.4 
51 
8. 14 
8. 1 
4.56 
2.0 
.048 
Trace. 
.048 
.040 
.0.55 
Nil. 
.424 
1.46 
.05 
July 20 
22.8 
48 
5. 35 
7.5 
7. 08 
2.0 
.095 
.028 
.067 
.016 
.040 
Nil. 
.672 
.77 
.04 
July 28 
26.7 
41 
6. 07 
3. 54 
3.5 
.013 
Trace. 
.013 
.048 
.040 
Nil. 
.864 
.79 
.07 
25.0 
36 
3.33 
7.5 
12. 64 
2.5 
.038 
.008 
.030 
.032 
.020 
Nil. 
.920 
1. 58 
. 15 
18.9 
41 
5. 22 
7.5 
12. 64 
3.0 
.028 
.010 
.018 
.048 
.015 
Nil. 
.800 
1.73 
.20 
22. 2 
48 
6. 28 
7.6 
11. 12 
2.5 
.058 
.003 
.055 
.024 
.025 
Nil. 
.800 
1.30 
.10 
23.3 
54 
5. 18 
7. 5 
11. 12 
2.5 
.095 
Trace. 
.095 
.032 
.019 
Nil. 
.360 
1.24 
.05 
ftp.pt io 
17. 22 
60 
5. 65 
7.5 
7.58 
2.0 
.090 
.032 
.058 
.024 
.027 
Nil. 
. 600 
.57 
.10 
Sept. 29 . 
n. i 
60 
7. 86 
7.5 
6. 06 
3.0 
.043 
.013 
.030 
.060 
.050 
Nil 
.460 
.96 
. 15 
.041 
.042 
.641 
1.41 
. 11 
