HYALINE SPHERES IN AURICULARIA OF STICHOPUS-JAPONICUS

The hyaline spheres (HS) in auricularia of Stichopus japonicus consist of extracellular material in which solitary cells are present. This e xtracellular material can be stained by dyes for lipids. There are no membranes or other structural elements in HS. The cells within HS are most probably responsible for secreting the extracellular material. HS are not embryonic inductors of the ciliary rings which appear during metamorphosis. They probably store nutrients which permit larvae to co mplete metamorphosis successfully, but this remains to be established.