The coelomocytes of Holothuria polii (Echinodermata). II. Cytochemical staining properties.

Histochemical studies by traditional staining methods for lipids, mucopolysaccharides and proteins and histoenzymatic reactions typical of lysosomal activity were carried out on the principal coelomocyte types of Holothuria polii. These are considered to be the cellular contigent of the immune response, and in Holothuria polii, they probably take part also in clotting events.