ABSTRACT
During the present winter Prof. S. J. Hickson kindly gave me an opportunity of examining1 the material from Jamaica in which he discovered the female Medusas of Millepora (‘99). The results of my inquiry are mainly concerned with the manner in which the symbiotic zooxauthellæ, found to exist in the free ova of that genus, infect the germ cells. I also wish to record the occurrence of free male medusai amongst the free female meduste collected in the above locality, and to make some remarks upon the oogenesis.
I have adopted the now very generally accepted terms of kineto-nucleus and trophonncleus for the small and large nuclear* bodies respectively. These terms seem to me to express more adequately than any of those hitherto proposed the nature and function of these two structures. In this paper the expression “anterior “end is used as equivalent to the flagellate end, “posterior “end as equivalent to nonflagellate end. The evidence in favour of this view being correct seems quite convincing when one has regard to those Trypanosomes in which the Trypanosome phase is derived from a Crithidial or Herpetomonad form in the normal life cycle. The evidence for regarding the flagellate end as the anterior* is not so clearly indicated in Trypanosomes which adopt the crithidial or herpetomonad condition by the mere alteration in shape of the body and the migration towards the flagellate end of the already existing flagellum. This development, as is well known, is said to occur in the cultured forms of a very large number of different Trypanosomes, notably those of birds and mammals.
Mi-. W. A. Harding, who kindly examined the leeches brought from Ceylon, considers this leech to be Limnatis (Poecilobdella) granulosa.
Ozobranchus, a species of this genus of leech is found in great numbers upon Nicoria trijuga. Mr. Harding states that this is a new species.
