20 



K. MITSUKURI. 



As to the means of proleciing and, if possible, of propagating and 



increasing these holothurians, it seems to me that their habits of 

 moving about forbid that their living place should be divided into lots 

 to be leased to different private persons as in the case of the oyster or 

 of other molluscs. The measures of protection and propagation must 

 be made to extend over at least one sea-division, or section, or district, 

 and must be taken hold of by some governmental authorities or 

 Fisheries-associations with the hearty cooperation and adherence of the 

 fishermen themselves. Ina section where such protective measures are 

 tobe put in force, two things ought to be done: — in the first place, 

 some localities where these holothurians arc found in a tolerable 

 abundance, should be selected as breeding reserves and here all fishing 

 should be prohibited throughout the year. In the second place, either 

 in these reserves or in other convenient localities, piles or dikes of loose 

 stones with plenty of nooks, crevices, or dark passages large and small 

 should be constructed in shallow water to afford the summer retreat 

 to the adult and sheltered spaces for the metamorphosing larvae and 

 young holothurians which will naturally collect at such places. It seems 

 best to me that such piles or dikes should be in lines perpendicular to 

 the shore line so that there may be various depths of water. The 

 quantity of the catch of a given district on one hand and the supply 

 of animals afforded by the breeding reserves and propagating stone- 

 dikes and by animals outside the reserves, on the other hand, must be 

 studied and the balance between them must be carefully maintained, or 

 if the increase is desired, the supply must be made greater than the 

 amount of the catch. The size and number of the breeding reserves 

 and the extent of the stone-piles or dikes to be constructed must be 

 studied separately for each particular region. Some of these measures 

 have been put in force in a part of the Mikawa Bay in the Aichi 

 prefecture, although the results are not yet reported. 



After I had thought out these measures of protection for Stichopus 

 japonicus from its habits and life history, my friend Dr. KlSIIINOUVE was 

 travelling in the somewhat out-of-the way island of Oki and found that 



