62

Scientific Memoirs by

lity of bird-introduction is greater, for Premna the probability is in favour of
introduction by the sea.

    Herpestis and Oldenlandia are marsh plants with small seeds that might
easily be conveyed in pellets of mud attached to the feet of wading birds.
They clearly may owe their introduction to this agency, and are the only Lac-
cadive species for which this mode is the only conceivable one. But this agency
may possibly account for the introduction of some of the grasses as well, and
by no means improbably explains, at least in part, the distribution of one of the
sedges.

    The spores of both ferns are almost certainly wind-introduced; the wind
probably also explains the presence of Cynanchum and Tylophora, not impro-
bably the presence of Crepis and Calotropis, and possibly, though this is less
likely, the presence of Gloriosa.

    The other twelve are coast species, and have almost certainly been all intro-
duced by the sea. They are—

      Suriana maritima.

      Guettarda speciosa.

      Launea pinnatifida.

      Scævola Koenigii.

      Tournefortia argentea.

      Ipomœa biloba.

      Hernandia peltata.

      Euphorbia Atoto.

      Cyperus arenarius.

      Cyperus pennatus.

      Spinifex squarrosus.

      Lepturus repens.

One of them (Cyperus pennatus) occurs on mud flats in tidal estuaries, as
well as on open shores, and may owe its distribution at least in part to the feet
of wading birds. For the others the distribution is clear. But there are
several species concerning which the evidence is hardly less doubtful. These
are—

      Cæsalpinia Bonducella.

      Morinda citrifolia.

      Ipomœa grandiflora.

      Premna integrifolia.

      Pandanus odoratissimus.

      Cocos nucifera.

But there are others still, all already alluded to and more or less exhaus-
tively discussed, for which an ocean-distribution is quite conceivable. They
are—

      Calophyllum inophyllum.

      Thespesia populnea.

      Bœrhaavia repens.

      Aerua lanata.

      Achyranthes aspera.

      Apluda aristata.

and there are a few others for which the possibility is so slight that they need
not be again mentioned.

    The number and proportion of the species that have been certainly, or
possibly, or probably influenced in their introduction by the various agents of
distribution are more easily appreciated when shown in the form of a table—