202 
BULLETIN OF THE BUREAU OF FISHERIES 
of Nitzschia growth is apparent in both media. An analysis of the results of all 
the experiments with brine summarized in table 23, shows that the retarding effect 
is more apparent in the sea water than in the Miquel solution. A 12-percent con- 
centration of brine causes only 10 percent retardation of Nitzschia growth in the 
Miquel solution, whereas in the sea water retardation averages 41 percent. 
Table 23. — Retarding effect of brine on the growth of Nitzschia culture 
[Figures in the body of the table indicate percent of retardation] 
Concentration of brine 
Dec. 23 
(16 days) 
Jan. 8 
(22 days) 
Feb. 2 
(31 days) 
Feb. 2 
(31 days) 
Apr. 2 
(14 days) 
Apr. 2 
(14 days) 
Average 
percent of 
retardation 
Percent in Miquel solution: 
12 
23 
11 
0 
12 
8 
8 
10 
18.8 
48 
3 
36 
17 
26 
25 
58 
28 
40 
38 
35 
30 
38 
37.5 
75 
63 
69 
50 
93 
90 
92 
Percent in sea water: 
12 
13 
66 
40 
46 
41 
18 
36 
74 
61 
57 
25 
31 
75 
79 
80 
66 
37 
76 
87 
82 
50 
77 
99 
88 
