THE "AGGLUTINATION" PHENOMENON WITH SPERMATOZOA OF CHITON TUBERCULATUS

¹ From the Bermuda Biological Station for Research

1. When dry sperm of a mature male Chiton tuberculatus is introduced into the mantle cavity of a male or immature female and the discharged sperm is collected and examined immediately with a microscope, the spermatozoa will be seen to come together and form small clumps. The point of attachment of these clumps is the tail, while the heads remain perfectly free.

2. These clumps fuse readily to form either large spherical masses, or strands, which, in turn, soon fuse with other strands to form extensive networks. Such structures also form, readily and extensively, when the two drops are fused with the aid of a glass needle in a way such that the sperm suspension is distributed widely throughout the drop of sea water.

3. On the other hand, when extracts from the ovaries of ripe or spent females, egg-sea-water, body juices of a mature male, or of a mature female, or sublethal solutions of the lytic substances, saponin or sodium taurocholate, are used, no clumping in any form occurs. Instead, the spermatozoa in the advancing edge of the drop of dry sperm move freely, and the sperm mass progresses steadily until the far side of the drop of diluting fluid is reached.

4. These observations indicate that, in Chiton tuberculatus, the clumping reaction rests fundamentally upon the presence, on the outside surface of the spermatozoön tails, of a substance which (1) is distinctly sticky in nature, and which (2) can be dissolved or destroyed by certain substances.