1. On the Ciliation of Asterids, and on the Question of Ciliary Nutrition in Certain Species.

Authors

  • James F. Gemmill M.A., M.D., D.Sc., F.Z.S.


Summary.

A. Ciliary Action.—The arrangement of the ciliary currents on the various surfaces of four widely different species of Starfishes has been described in detail. This arrangement is constant for all individuals in each of the species, and, except as regards external surfaces, is practically the same in all the species. Everywhere the arrangement has been shown to be explicable by physiological needs. Ciliation in the perihæmal spaces has been demonstrated.

B. Ciliary Feeding.—In the case of Porania pulvillus a mechanism for ciliary feeding has been shown to exist, and the results of experiment demonstrate that this kind of feeding actually takes place. As regards Astropecten, it is only shown, so far, that the arrangement of the actinal and abactinal cilia makes ciliary feeding possible. In Solaster papposus ciliary feeding probably takes place, but in an entirely minor degree. The other Starfishes examined gave negative results. The important bearing of the above results on questions of phylogeny is briefly discussed.

Ancillary