ON THE CALCAKEOUS DEPOSITS OF STICHOPUS JAPONICUS. 35 



tion in either way, the overhauling of a large number of specimens of 

 both sexes, at various stages of growth and from all sorts of localities 

 was a necessity. Fortunately, I had been slowly accumulating just 

 such a collection, in course of the inquiry undertaken with the 

 above-mentioned economic object at the request of the Ministry of 

 Agriculture and Commerce. Moreover, from the experience thus 

 gained, I found it possible to tell within certain limits the age of a 

 given " namaho " and obtained the knowledge of when and where 

 individuals of certain sizes might be found.* I thus flattered myself 

 that I had favorable opportunities for settling the question put forth 

 above in regard to the calcareous deposits of the " namaho. " 



I shall now briefly set forth the results of my study on this ques- 

 tion : — 



The holothurians commonly known in Japan under the name 

 of the " namaho " all belong to one species, viz.: — Stichopus japo- 

 nicus, Selenka. The form distinguished by Théel as var. 

 typicus is only a stage in the growth of the species. Holothuria 

 armata, Selenka may possibly be better set down as a variety of 

 this species, not, indeed, on account of its calcareous deposits but 

 of some other characters as will become clear in the sequel. 



The form of calcareous bodies t changes with advancing age in 

 Stichopus japonicus. The youngest individuals have most perfectly 

 formed, large-sized tables and nothing but these. They have such 

 tables very thickly crowded or even overlapping with their bases. 

 With the growth of the animal, perfectly formed tables decrease 

 both in number and size, and tables in various stages of arrested 

 development are found mixed with them. The degree of imperfec- 

 tion in tables of arrested development as loell as the proportion of 

 such tables to perfectly formed ones constantly increase with age, 



* It is my intention to put together elsewhere the results of rny inquiry into the 

 habits and life-history of the " namaho, " together with my plan for the propagation of 

 the animal. 



t As before, I am not speaking of the terminal discs and supporting rods of the 

 tube-feet. 



