SPERM AGGLUTINATION IN THE KEYHOLE LIMPET, MEGATHURA CRENULATA

Abstract

The agglutination reaction persists in excess egg-water until after the death of the sperm but in great excess of sperm reverses spontaneously. Its longer duration in sea-urchin than in limpet correlates roughly with the time at which a precipitate forms on adding anti-agglutinin (sperm extract) to agglutinin (egg-water). The rate of agglutination with varying concs, of sperm suspension and agglutinin varies similarly to the zone phenomena in serological reactions. The sperm agglutinate by their tails and under certain conditions also by their heads but only tail agglutinin is present in egg-water; head clumping is probably a sperm aggregation concomitant with dilution of the suspension. This autq-agglutination reaction is interpreted to indicate that there is a partial dissociation of a surface substance as a result of change in pH or other conditions. Egg-water agglutinin is either the material of the jelly layer or some component of it in both urchin and limpet. The agglutination reaction in the limpet, although resembling hetero-agglutination, is both tissue and sp. specific. The agglutinates behave like liquid drops; apparently upon 1st reaction with the sperm agglutinin forms an insoluble liquid.