Sea urchin response to foreign substances.

An assessment of the response of Strongylocentrotus purpuratus to substances injected into the coelom shows that (i) foreign molecules are cleared from the coelomic fluid more rapidly than native molecules, (ii) coelomocytes can respond selectively to albumins of human and bovine origin, and (iii) immunization attempts fail to elicit accelerated coelomocyte uptake or accelerated clear-with antigen.