398 SUMMARY OF CURRENT RESEARCHES RELATING TO 



more or less developed oviducts. 2. Males whose testes contain eggs. 

 'd. Hermaphrodites with both kinds of gonads, the male predominating. 

 4. Perfect or almost perfect hermaphrodites. 5. Hermaphrodites with 

 both kinds of gonads, the female predominating. The great majority of 

 the recorded cases appeared predominantly males ; most of them might 

 be described as intermediate hermaphrodites, transition-il between female 

 and male. 



Fatty Bodies of Amphibians.* — P. Kennel has studied these organs 

 — which should be called " adipolymphoid " — in Anura (digitate lobes 

 in front of gonads), in La'odela (a simple or divided band alongside of 

 the gonads), and in Gymnophiona (a band extending from the posterior 

 end of the animal to the anterior third). He calls attention to his dis- 

 covery of very distinct lymphatic vessels, and brings forward evidence in 

 support of the conclusion that the organs are somatic not germinal 

 reserves. Tlie gonads have their own localized reserves. 



Transplantation of Frog's Gonads-f— Pi. Meyns has succeeded in 

 engrafting indifferent and differentiated gonads of the frog in adult 

 animals. Ovarian tissue, as well as testicular tissue, may be implanted 

 in a male frog. The young gonad continues its normal development 

 in the body of the adult. The transplantation of sexually mature testi- 

 cular substance into a non-castrated frog was ineffectual. Meyns has 

 observed that ova appear almost regularly in the tubuli of regenerating 

 pieces of frog-testis. 



Tunicata. 



Placenta of Salpa democratica-mucronata.| — C. Saint-Hilaire has 

 studied the development and structure of this remarkable organ. He 

 describes the so-called roof, the syncytium, and the side-walls. The 

 passage of nutritive material from the mother to the embryo is effected 

 mainly through the I'oof. The syncytium functions as the intermediate 

 stratum. It is spread out quite continuously under the roof, and 

 passes over on to the side-walls. The mesenchyme cells play an impor- 

 tant role in the utilization of the nutritive material. There is an 

 energetic circulation in the placenta, which persists even after the 

 embryo has left the maternal body. The analogies between the salp- 

 placenta and the mammal-placenta are very striking, not least that in 

 both we have an active ingestion of cell by cell. 



INVERTEBRATA. 



Mollusca. 

 y. Gastropoda. 



Memoir on Whelk § — W. J. Dakin gives a full account of Burcimim 

 undatum, and adds much to our knowledge of the minuter structure. 

 Thus he deals with the microscopic structure of the ctenidial leaflets, the 

 mucous gland, the alimentary canal, the odontophore apparatus, the eye, 



* Comptes Rendus, cliv. (1912) pp. 1378-80. 



t Arch. Mikr. Anat., Ixxix. (1912) pp. 148-76 (1 pi.). 



% Arch. Mikr. Anat., Ixxix. (1911) pp. 59-104 (4 pis. and 8 figs.). 



§ Rep. Lancashire Sea-fisheries Laboratory, xx. (1912) pp. 183-297 (8 pis.). 



