ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 627 



Effects of Starvation on Planarians.* — J. Berninger has made a 

 study of the effects of starvation on several species of Planarians. During 

 the course of the starvation period the Planarians lose about one-twelfth 

 of their normal size and length, the loss amounting to about one-twelfth 

 of the total volume. . No degeneration could be observed in the nervous 

 system or musculature as a result of starvation, and very little in the 

 intestine or parenchyma. In the absence of food and light the eyes were 

 totally re-absorbed in the course of 7 to 8 months ; the whole eye-orbit 

 divides into two, three, or more parts, the pigment breaks up, and finally 

 the optic nerves and cells disappear. In pigmented Planarians the body 

 pigment is also re-absorbed to a certain extent. The sexual organs are 

 without exception reduced and finally disappear. The yolks degenerate 

 first and are followed by the copulatory organs. With these the oviducts 

 and vasa deferentia disappear ; the ovaries then follow, and the testes 

 are re-absorbed shortly before death takes place. The cocoons are 

 reduced to about half their normal diameter, and the embryo rarely lives 

 till emergence. The embryos which do survive show in their reduced 

 size the effects of starvation. Planarians endure 3 to 4 months' starva- 

 tion fairly well. If they are well fed at the end of this period the 

 sexual organs may be restored, even though they have almost entirely 

 disappeared. 



Revision of Swiss Triclads.j — Paul Steinmann distinguishes rheo- 

 philous forms from flowing water, and limnadophilous forms usually 

 in stagnant water. A number live in darkness, Planaria alpina var. 

 bathyeola, and Dendroccelum lacteum var. bathycola from deep lakes, 

 Planaria vita from wells, Dmdromlum infernale and Planaria cavaUca 

 from caves. With the aid of very clear diagrammatic figures he gives 

 an account of the general structure of Triclads. A diagnostic key 

 to the genera and species of Swiss Triclads is then given. There are of 

 course no marine forms for Switzerland, and there is only one terrestrial 

 form — Rhynchodemus terrestris (Mull.)— so that the key is practically 

 to " paludicolous " forms. 



Malacobdella grossa.J — G. Gering has made a study of this Nemer- 

 tine. All his specimens were obtained from Cyprina islandica, usually 

 in large individuals. In one case four young ones were found in one 

 bivalve. Gering observed that although there is no stilet apparatus, the 

 proboscis is used as a weapon. The oogenesis and the spermatozoa, the 

 maturation, fertilization, and first cleavage are described. 



Rotatoria. 



Clare Island Rotifers.§ — James Murray reports on the Bdelloid 

 Rotifers collected at Clare Island, fifty-seven species, of which forty-eight 

 are additions to the Irish list. There is not a single species which is 

 confined to Ireland, and there is only one (excluding six doubtful ones) 

 which does not also occur in Scotland. One of the most interesting 



* Zool. Jahrb., xxx. (1911) pp. 179-216 (29 figs.). 



+ Rev. Suisse Zool., xix. (1911) No. 7, pp. 175-231 (3 figs.). 



X Zeitschr. wiss. Zool., xcvii. (1911) pp. 673-720 (1 pi. and 1 fig.). 



§ Proc. K. Irish Acad., xxxi (1911) Clare Island Survey.pt. 52, pp. 1-20 (1 pi.). 



