Mast (1914) has shown that light perceived by the 
eyes of a fish may be the stimulus causing changes in 
the coloration of the skin. Other investigators have 
shown that modifications in coloration may be caused 
by anaesthetics or adrenalin, (epinephrin) etc. Excess 
of acids or alkalies in the water also cause changes in 
color. 
It therefore is pointed out that problems dealing 
with the physiology of fishes are apt to lead into many 
phases of physics and chemistry not clearly under- 
stood when applied to living fishes. 
D. R. CRAWFORD 
College of Fisheries 
SOME EMBRYOLOGICAL NOTES OF 
HYNOBIUS NAEVIUS1 
Hynobius naevius (Schlegel) ("Buchi-sanshou'")2 is 
a salamander indigenous to Japan. It lives near a 
mountain stream, and spawns usually under stones in 
the stream in the later part of March. A pair of egg- 
sacs, each containing some fourteen or fifteen eggs, 
are laid at a time. The egg is white in color, with 
much yolk, and has a diameter of about 5 mm. 
In a week after spawning, gastrulation is completed, 
and soon after this neural folds are formed. For the 
completion of the neural groove about ten days are 
required. 
After a fortnight the fusion of the neural folds takes 
place and the head part is distinguishable. In two or 
1. Contributions from the Zoological Laboratory, Kyflshfi Imperial Uni- 
versity, No. 16. 
2. Buchi, spotted or mottled; sansh~uo, salamander. 
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