HABITS AND LIFE-HISTORY OF STICHOPUS JAPONICUS. 



When in one and the same individual, the reproduc- 

 tive glands grow from 2—3 cm. to 30 cm. or more, 

 how futile it is to describe their length as a 

 characteristic to be used in a specific diagnosis ! 



There are often seen even at the 

 height of the breeding season, in front 

 of such fully grown tubes other small 

 and delicate tubes which look as all 

 the reproductive tubes do in the early 

 autumn before they begin to grow at 

 all. These are probably 

 a part of those which 

 will grow and ripen in 

 the following year. I 

 have long suspected 

 that the reproductive 

 tubes in the Hnlo*hitr 



ans ought to be regarded 

 simply as local lateral groivtlis 

 of the reproductive elements or 

 Keimplasma which is lodged 

 in the median line of the 

 dorsal mesentery. In order to 

 accomplish reproduction this gene, 

 rathe material has to increase 

 immensely in mass and in con- 

 sequence of this increase has to 

 produce lateral growths in the 

 shape of branching tidies of which 

 there is a certain number produced 



