430 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the young are all hatched by the first half of July, while PI. gonocejphala 
reproduces from the beginning of July to the beginning of September; 
its young have, therefore, less time to lay up stores for the winter. Thus 
the short summers of the Ice Age would be more fatal to PI. gonocejphala 
than to the others. Voigt has much more to say than we have space to 
notice, but enough has been cited to suggest the thoroughness of his 
careful inquiry. He invites the co-operation of other naturalists to 
assist in the more complete working out of the problem. 
Land Planarians from the Blue Mountains, New South Wales.* — 
Prof. A. Dendy describes nine species obtained in the Blue Mountains, 
of which seven are known to be represented in Victoria by identical or 
slightly varietal forms. Of the remaining two, one has been found in 
Tasmania, and the other is represented in Victoria by a closely allied, 
if not specifically identical form. Prof. Dendy takes the opportunity of 
revising the nomenclature of the common and widely distributed Geo- 
jplana sanguined. 
Asexual Reproduction of Freshwater Turbellaria.j — Herr J. Keller 
describes this in Stenostoma Langi sp. n. About the middle of the 
intestinal region a new brain is formed, and at the same place a new 
pharynx appears medio-ventrally. Olfactory grooves and eyes follow. 
About 24 hours after the beginning of the “ regeneration,” the animal 
begins to constrict in front of the new organs. The original individuality 
is lost in forming two equivalent zooids, for the anterior part cannot be 
called the mother. On an average this process of paratomy takes a 
week ; it is slower, and the zooids are smaller in winter ; it seems to 
occur all the year round except in some weeks of October, when large- 
sized hermaphrodite forms occur. These do not die after reproduction, 
as has been stated. 
Keller describes for the first time the two eyes of Stenostoma. The 
vesicle consists of a single layer of epithelium, at the posterior end of 
which there is one large (retinal) cell with a refractive body (rhabdome) 
towards the centre of the vesicle. A ganglion cell connects the retinal 
cell with the brain. There is no pigment. 
The brain is wholly regenerated from unbranched connective tissue 
cells ( Stammzellen ) ; the olfactory pits arise from modification and in- 
vagination of epidermic cells ; the eyes, the pharynx, the skin-glands of 
the head are all regenerated from Stammzellen, which also form the 
gonads. The new protonephridium is formed from the cells of the 
original longitudinal canal. 
Hermaphroditism of Prorhynchus.J — Mr. J. Percy Moore rightly 
remarks that unisexuality is so nearly universal among the Nemertines 
that an additional case of hermaphroditism is of interest. Two speci- 
mens of P. tenuis found near Philadelphia were clearly seen to be 
hermaphrodite. The number of genital sacs is very much reduced, and 
the gonads are not regularly paired. In no case was a distinct com- 
munication with the exterior observed, though contact with the skin is 
frequently very intimate. In the two undoubtedly bisexual individuals 
* Proc. Linn. Soc. N.S.W., ix. (1895) pp. 729-34. 
t Vierteljahrschr. Nat. Gesellsch. Zurich, xxxix. (1894) pp. 337-44 (1 fig.). 
% Zool. Anzeig., xviii. (1895) pp. 63-5 (2 figs.). 
