- TRANSACTIONS OF WAGNER 
ON THE LIFE HISTORY OF AN ECONOMIC CUTTLEFISH OF JAPAN 
20 
that the cuttlefish, that were found scattered over the horizontal extension of 
the warmer water when this was expanded, are carried up with the water in 
which they lived, so as, so to speak, to be crowded in the narrow zone just 
mentioned and can easily practice their daily vertical migration, having 
temperature suited for themselves at every stratum. As it is in coincidence 
as regards the season, the large catch above referred to can certainly be em- 
ployed as an illustration of this occurrence. 
Let us now examine the ecologic relation of the cuttlefish to the two other 
currents, 7. e., the Oya-shiwo and. Kuro-shiwo. With regard to the first 
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TG aS 
Hydrographic section off Iwaté-ken, showing vertical distribution of water temperature on Nov. 1, 
1919 (from a hydrographic observation made by the Fishing Experimental Station of Iwaté-ken). 
current, I have already alluded above to its relation to the distribution of the 
animal. In a comparison of the map of currents (fig. 6) with that of the 
population of the creature (fig. 1), one would not hesitate to recognize that 
this current is by no means favorable for the cuttlefish, owing, as mentioned 
above, chiefly to its low temperature. The unfitness of the colder current in 
this respect is most obvious at the coast of Fushima-ken, and also at the 
eastern coast of Hokkaidé (Tokachi): both the places stand alike at the front 
of the lands, against which the current strikes, flowing straight down from a 
region east of Kamchatka. 
Concerning the latter locality, a zone of relatively warmer water in which 
