FREE INSTITUTE OF SCIENCE 
ON THE LIFE HISTORY OF AN ECONOMIC CUTTLEFISH OF JAPAN 
13 
The second experiment was performed on the succeeding day at about the 
same hour as the first. The material consisted, in this case, of one male and 
two females caught at the same part of the sea as in the last case, and unfor- 
tunately all the specimens were found dead twenty minutes before reaching 
my hand. The eggs I took out of the oviducts of the female as in the last 
experiment, but the spermatozoa were prepared from two different sources: 
firstly from the spermatophores of the buccal membrane of the females, and 
secondly from the spermatophores of Needham’s sac of the male. Notwith- 
standing the experiment had been carried out as carefully as possible yet the 
rate of fertilization was much lower than the former experiment, the fertilized 
eggs being 10 % of the whole eggs treated with the spermatozoa from the first 
source and 5 % of those with the second. This low percentage of fertilization 
compared with the former occasion is undoubtedly due to the genital elements 
having been taken from dead individuals. The development was also not nor- 
mal but mostly pathologic. Their final fates were the same as in the last. 
Due to the bad condition of the sea, I had no opportunity for further ex- 
periment. At all events, however, from the two experiments referred to, I 
convinced myself that the artificial fertilization of the species in question is 
not difficult at all, wherever living material can be obtained, and that only one 
female is enough to afford the sexual elements for an experiment, and further 
that the early development does not widely differ from that of Loligo. More- 
over, I call attention to the fact that the eggs remained on the bottom of the 
basin throughout the development so far examined, because this shows the eggs 
to be demarsal in the natural state also. 
RELATION OF PHYSICAL CONDITION OF SEA TO HABIT OF 
NIBAN-SURUME 
The daily catch of the cuttlefish fluctuates very irregularly. This is, per- 
haps, largely due to the biologic characteristics of the cuttlefish relating to its 
food and enemies, as mentioned before (p. 4). These are, of course, combined 
with daily and seasonal changes of hydrographic and meteorologic conditions, 
which control the work of the fishermen. For instance, in autumn and winter 
the Japan Sea is usually so very rough that only the strongest and most skilful 
men can practise the fishery, and this, only in relatively quiet parts of the 
sea, sheltered from wind; this diminishes greatly the crop of the season, 
