METABOLIC ACTIVITY OF NERVOUS SYSTEM 45 
ing the brain from the spinal cord in the mammalian nervous 
system. Anteriorly the olfactory nerves were cut close to the 
olfactory bulbs. The saccus vasculosus was not included with 
the brain. The brain which was thus removed was placed in 
a small bottle which had been previously weighed, and this was 
weighed again to a milligram. After the fresh weight of the 
brain was determined, the bottle with its contents was placed 
in a steam oven at a temperature of 80°-90°C. for several days 
(Tortugas laboratory) and then later dried at the Wistar In- 
stitute under better laboratory conditions at 96°C. The various 
other methods used for the analysis of the brain will be de- 
scribed later. 
THE BRAIN WEIGHT IN RELATION TO BODY LENGTH 
Altogether observations on 74 brains of the gray snapper have 
been made. 
From table 1 the average brain weight of the sanpper for 
several values of the body length has been calculated and the 
results are given in table 2. : 
In order to show the general distribution of the brain weights 
in relation to the body length, I have prepared a chart based 
on the data given in tables 1 and 2. 
In the chart males and females are not distinguished. As will 
be seen from chart 1, the distribution of brain weight in respect 
TABLE 2 
Showing the average brain weight of the gray snapper for the several values of the body 
length 
BRAIN WEIGHT 
BODY LENGTH BODY LENGTH NUMBER OF 
RANGE OBSERVED @beeea Capaned by SNAPPERS 
mm. mm. 
200-250 231 0.643 0.667 10 
250-300 271 0.860 0.840 23 
300-350 319 1.037 1.048 15 
350-400 373 1.296 : 1.282 12 
400-450 428 1.513 1.520 a 
LSE AE A OS. Od Ot oad OF 1.070 1.071 
