PREESINSPIPUME (OF sSClENCE 15 
ON THE LIFE HISTORY OF AN ECONOMIC CUTTLEFISH OF JAPAN 
1905 5,536,889 kan* 1912 16,489,756 kan 
1906 6,496,634 “ 1913 19,257,698 “ 
1907 8,333,680 1914 20,210,660 “ 
1908 4,802,423 IQI5 12,095,727 
1909 5,173,717 1916 §=21,913,438 
1910 7,726,278 1917 17,880,940 
IQII 9,153,038 
* 7 kan=ca. 3.8 kilos. 
73 
ce 
cé 
6c 
cc 
66 
a 
n 
” 
n 
This increase iS = Kan(=ca.s.sx) 
43000000 
probably due to the in- 
crease Of) professional) 7) 
population as well as 
IM PrOVEMent wOhu a yess 
the 
fishing methods and 
statistics. At any rate, 
however, it is true that 
there is seen even no 
tendency towards de- 
10000000 
9000000 
crease. 8.000000 
is 
From what 
700000 | 
wy 
rg 
£ 
s 
s 
§ 
$ 
z 
above said, the eco- g 
es) 
logic changes, if there gy 
r) 
have really been such 
changes, can not neces- 
sarily beassumed tobe °°” 
caused by fishing with- 
out control. an 
The third factor 
° 3000000 
which comes under 
consideration is that veh / 
i 2000000 | °° via / 
due to the physical con- ; 
ditions of the sea. Set- / 
i x i 1000000 
ting aside the daily and 
seasonal changes, and 
those, as rarely hap- ib was 
pens, by volcanic agen- Fic. s. 
cles, we See a great fac- Curves of the annual catches of Nibanzurumé in Niigata-ken 
é : and Hokkaid6, compiled from the Statistical Reports of the Agri- 
tor in the hydrographic cultural and Commercial] Bureau of Japan. 
v 
6000000 
3 
§ 
~ 
¢ 
3 
& 
ro 
3 
v 
Bo 
a) 
wi 
Sy 
w 
3 
§ 
© 
Curve of the annual catches of the cuttlefish. 
Lace -y «6 Niigata-ken 
ert 
~ > 
x 
(ie 1913 IIS G7 Year 
