48

Scientific Memoirs by

      Sluiter, Zool. Anzeiger, 1888 p. 240 (fish and sea-anemone).

      Other references will be found in some of the above papers.

II.—Some Notes on Sexual Characters, Pairing, and Viviparity
among Marine Animals.

      It has been remarked that the one final end of the individual existence is the
upkeep of the species, and that most of what we are accustomed to regard as
the purpose of life is merely the outcome of the sustained effort to fulfil this end.

      If from this broad standpoint we compare the activities of animals that live
in the sea with those of animals that live on land, it often seems as if—especially
in respect of those direct efforts involved in courtship and parental care—the
lives of sea-animals are the simpler and the less purposive.

      Any observations, therefore, which tend to show that the behaviour—
especially the sexual and parental behaviour—of marine-animals is not very dif-
ferent from that of land-animals, will be of interest to the evolutionist.

1. On Pairing and Parental Care among Echinoderms.

      Darwin (Descent of Man, 2nd edition, page 260) states definitely that
secondary sexual characters do not occur in this phylum.

      As to pairing among Echinoderms, the only reference that I can find is that
of Jickeli in Zoolog. Anzeiger 1884, page 448 (translated in Ann. Mag. Nat. Hist.
ser. 5, vol., xiv, 1834, page 367). My own observations on the reefs of these
seas had led me to believe that among both Ophiuroids and Asteroids pairing
takes place, and in January 1890 I obtained actual proof of the pairing of Ophio-
campsis pellicula.

      When dredging off the Orissa coast in 11 fathoms, two individuals of this
species were found woven together in the closest embrace in the recesses of a
Pennatulid colony. One of them had the disk greatly distended with what under
the microscope proved to be ova, the other was a male, much less tensely charged
with spermatozoa.

      With regard to the care of eggs and young, including viviparity, although
this is well known to occur in all classes of Echinoderms, except Crinoids, yet on
the " Investigator " we have made no observations on this point, except to verify
the fact that the star-fish Marsipaster carries about its eggs in an abactinal
brood-pouch. From the fact, however, that Pluteus and other free-swimming
larvæ of Echinoderms are not nearly so abundant as one would expect in these
seas, it is reasonable to suppose that viviparous and nutricant species will be