54. SHINKISHI HATAI 
TABLE 6 
Showing nitrogen content in terms of the non-proteins, the amino acids, the urea 
and the ammonia, in the brains of the gray snapper and of the ‘schoolmaster.’ 
BRAINS MILLIGRAMS NITROGEN PER 100 GRAMS OF FRESH BRAIN 
SERIES ; Undeter- 
Number Weight a genet Urea Ammonia panel 
nitrogen 
Neomaenis griseus 
gms. 
1 16 13.166 204 101.8 13e2 geez Te3 
2 13 10.713 224 125.0 17.8 18.9 62.3 
3 15 12.048 203 L212 ozs 7/2! 48.6 
AVERAGE? Eo. ries 11.976 210 116.0 15.6 18.0 60.7 
Neomaenis apodus 
i | 10 | 11.195 | 295 | 126.0 | 17.3 | 17.2 | 64.5 
This agreement in the various substances might also be taken 
to support the belief of the systematists that these two species 
are closely related. 
COMPARISON BETWEEN THE GRAY SNAPPER AND THE ALBINO RAT 
IN REGARD TO THE CHEMICAL COMPOSITION OF THE BRAIN 
In order to compare the data on the chemical composition of 
the brain in the gray snapper with those for the brain of the 
albino rat, table 7 was prepared. The entries for the fish are 
based on tables 5 and 6, while the data on the albino rat were 
obtained from. an earlier paper (Hatai, 717). 
When comparison is made between the fish brain and the en- 
tire brain of the albino rat, we find a distinct difference in regard 
to the content of the total nitrogen and of the nitrogen in the 
lipoids, as well as in the total amount of the ether-alcohol ex- 
tractive materials. These differences must undoubtedly be 
correlated with anatomical differences in the two forms of the 
brains. In the rat we find a well developed cerebrum and cere- 
bellum in which the myelinated nerve fibers are relatively less 
than in the stem, while the cell bodies are more abundant. On 
the other hand in these fish brains we find a mere trace of the 
