TRANSACTIONS OF WAGNER 
ON THE LIFE HISTORY OF AN ECONOMIC CUTTLEFISH OF JAPAN 
14 
even though the cuttlefish are as much crowded as in summer when the 
sea is usually quiet. 
The above fluctuations of the crop are, however, a rather usual occurrence. 
Since some ten years ago, cases of great decrease of the catch have occurred 
from causes quite unknown to the fishermen. The chief provinces where this 
unfortunate condition has continued to occur are Sado, Oki, Tsushima and 
Utsuryoté6. In all these places, it is said, formerly the cuttlefish were abundant 
the whole year, being most numerous in summer. In this season the sea is 
usually quiet as mentioned above, and the fishery can be carried out with ease 
so that formerly it was very successful, along the whole coast of the islands, 
so as to bring the total annual catch to a great amount. In recent years, 
however, this has been greatly changed, the cuttlefish being as a whole very 
scarce and the season when they are most abundant is not the summer but 
autumn or even winter, or, as in Sado, at every season they are so scarce that 
the catch does not pay for the labor. What is then the factor which caused 
the barrenness of the fishing places and the change of the shoaling mode of 
the cuttlefish? Not only from the economic point of view but also from the 
theoretic, we have to clear up this question which forms the final chapter of the 
present investigation. 
Confronted by such a problem as this, one might assume as the causal 
factors uncontrolled exhausting fishing of the creature under consideration, 
together with the ecologic changes which may take place in consequence of 
such an irreplaceable catch as noted. These are, it seems to me, in reality not 
the principal factors, for the decreased crop in one province is compensated by 
the increase in others, so that the total catch is not changed. As a good ex- 
ample of the reciprocal change of catch, I refer here to the case between Hok- 
kaidé and the prefecture to which the famous fishing place of Sado belongs, 
Niigata-ken. In Hokkaid6é the annual catch has been increased year after 
year, while in Niigata-ken the opposite has been the case, showing a decrease 
roughly proportional to the increase in the former, as seen from the annexed 
curves (fig. 5). 
The further our studies go, the clearer is made the fact that there is no 
evidence of decrease at all, but rather a great increase, in the total annual catch. 
As seen in the following table which represents the total annual catch from 1905 
to 1917 reported by the Bureau of Agriculture and Commerce: 
