K. MISTUKURI. 



Toward the end (June) of the second year, it is well nigh impossible 

 to distinguish the second year young from the adult. It must therefore 

 be concluded that Sticliopus japonic us reach the adult condition in 

 two whole years. 



This conclusion is borne out by the condition of the reproductive 

 organs in the young. The first year young do not as a rule have their 

 reproductive glands develope for breeding at the end of that year. 

 There may occasionally be some individuals with the larger and smaller 

 number of the reproductive tubes elongated but these are exceptions. 



At the end of the second year many individuals have their 

 reproductive organs develope, but by no means all the individuals. 

 Those that do not ripen are probably the younger of the same year's 

 crop. Only two or three tubes may grow elongated. Moreover even 

 in those that ripen, this takes place later than in the larger and adult. 

 At the end of July, when most of the larger ones have retired under 

 shelter, some of the second year ones are still shedding reproductive 

 elements. 



SticJiopus japonicus afte?' reaching the adult condition at the end 

 of the second year goes through a regular spazuuing season only at the 

 cud of another year i. c. the third year from the beginning. 



How many years these holothurians live after the adult condition 

 is reached I have had no means of ascertaining. Some of the largest 

 adult in my records are as follows: — 





Length 





Breadth 



r. 



26 



X 



7 



2. 



32 



X 



9 



3- 



3« 



X 



9-5 



4- 



43 



X 



7 



5- 



40 



X 



t'-' 8 



Such huge-sized ones stand out prominently even among a lot of the 

 adult holothurians, and I can not help having the impression that they 

 are one year older than the ordinary run of the adult holothurians* or 



* For the measurements of these, see the tables in the earlier part of the present article 

 prepared for determining the breeding season. 



