CULTIVATION OF MARINE ANIMALS IN JAPAN 719 



system of oyster-culture. Here the main part of the grounds is in a 

 sheltered inlet, or rather in an enlarged mouth of a river, which natur- 

 ally brings down a great deal of fresh water. As I think, for this very 

 reason the spat-collecting is done just outside the inlet. Here, in 

 April, when the breeding-season begins, bamboo collectors, four or 

 five in a bundle, are planted in close clusters along the channel to 

 receive the spat. At the end of the breeding-season, that is, in the 

 latter part of August - - the collectors are uprooted and conveyed 

 inside the inlet, care being taken not to injure the spat upon them. 

 There they are built into peculiar structures called "toya," which 

 are round-pryamidal in shape, and measure about three to four feet 

 high and five to six feet across at the bottom. A "toya" is con- 



FIG. 7. Bamboo collectors arranged after the fashion common in Kusatsu. They 

 stand about 3 feet above the bottom and their tips diverge; the clumps are set 

 4 or 5 feet apart. 



structed (Fig. 8) as follows: In the centre are small bamboo collectors 

 of last year on which some young oysters are still adherent. Outside of 

 these the new bamboo collectors, which have just been brought in 

 from the spat-collecting ground with tiny oysters adherent on them, 

 are placed in two circles, one outside the other, the bamboo branches 

 being made to interlock. The "toyas" are left in this condition ex- 

 actly one year, when they must give place to the next new set. 



The oysters that are now in their second year and are of a fair size 

 are struck off the bamboo collectors, which are rotten by this time, 

 and are then placed in the living-ground, where they lie directly 

 on the hard and gravelly bottom. They are left here until the next 

 year, although they are given a thorough raking every fortnight or 

 so. By autumn of the third year they are ready for the market. The 

 sea-bottom in the inlet of Nihojima has been completely utilized 



