48 SHINKISHI HATAI 
contrasted with the observed values. The agreement is highly 
satisfactory, and thus the formula may be employed when the 
probable brain weight of the gray snapper in which body length 
is known, is desired. I may point out that the absolute amount 
of increment of the weight of the brain following every milli- 
meter increase of the body length is slightly over four milligrams 
(4.33 milligrams). 
PERCENTAGE OF WATER IN THE BRAIN 
Altogether 64 snappers were examined to determine the water 
content in the brain, and the results have been already given 
n table 1. An examination of the table reveals several strik- 
ing relations in regard to the percentage of water. The per- 
centage of water given by the smallest fish is 78.85 per cent while 
that of the larger fish, having a body length of 424 mm. and 
ranking in length third from the largest in which the water de- 
termination was made, gives 78.54 per cent. The frequency 
distribution of the percentage of water gives the following 
results. 
TABLE 3 
Showiny the frequency distribution of the percentage of water in the brain of the 
gray snapper 
PER CENT OF WATER NUMBER OF CASES 
75-76 2 
76-77 5 
77-78 : 15 
78-79 : 17 
79-80 16 
80-81 6 
81-82 2 
82-83 1 
Totalsnumibersa eee eee One eee 64 
Despite the fact of a wide range in the percentage o° water, 
the distribution of the frequencies is practically normal, and fur- 
thermore the high and low values are well mingled, when these 
