830 SUMMAEY OF CURKENT RESEARCHES RELATING TO 



After a full account of the innervation of the heart, the author 

 passes to the buccal cavity, the minute structure of which is described 

 in detail ; different areas of the mucous membrane were found to 

 differ in reaction, that of the floor of the mouth being always acid, 

 while the lips are neutral, and the lateral processes in which are found 

 the orifices of the buccal glands are always alkaline. Especial atten- 

 tion is directed to the goblet-shaped cells, and the characters of the 

 buccal glands. 



Existence of a Shell in Notarchus.* — Vayssiere has demonstrated 

 the existence of a minute internal spiral shell in Notarchus. Taken 

 into consideration with a similar discovery by Krohn in Gasteropteron, 

 the author thinks it very probable that both are persistent embryonic 

 shells (in Notarchus it is about one-fiftieth as long as the animal 

 itself), and that an analogous appendage will be found eventually in 

 most Tectibranchs which up to the present time have been considered 

 shell-less. 



Differences between the Males and Females of the Pearly 

 Nautilus.! — A. G. Bourne bases his observations upon the dissec- 

 tion of two specimens, male and female respectively — both adult and 

 well preserved — of N. poinpilius obtained by Prof. Lankester for the 

 museum at University College, and a specimen of N. macromphalus 

 placed in his hands for examination by Prof. Hubrecht, of Utrecht 

 University. The author regards the tentacular lobes as homologous 

 with the arms of a Dibranch, while the tentacles probably represent 

 the suckers, this view, which has already gained considerable ground, 

 receiving very strong support from the hectocotylized condition which 

 the author describes. Eight tentacular lobes may be recognized : four 

 internal, two superior, and two inferior, the latter two being fused 

 together, and four external, the two superior being fused to form the 

 " hood," and the two inferior completing the external ring. In the 

 male four tentacles of the left superior internal lobe become hectocoty- 

 lized, while the corresponding four upon the opposite side exhibit 

 an exactly similar modified condition, though in a very slight degree, 

 forming a most interesting example of a " rudimentary organ." In 

 the male the inferior internal lobes are present in a very much reduced 

 condition. 



Molluscoida. 



Structure of Tunicates.J — L. Eoule discusses especially the 

 views of Prof. Herdman on the hypophysis cerebri of the Tunicata;' 

 he doubts the renal nature of the hypoganglionic gland, in the lobules 

 of which he has never found any trace of urates. Moreover, he 

 believes that a true kidney is present in these forms. Eoule is of 

 opinion that the gland in question is charged with secreting the 

 mucus which agglutinates the bodies brought in by the current of 



* Journ. de Conchyl., xxii. (1883) p. 4. See Scieuce, ii. (1883) p. 206. 

 t Prnc. Brit. A-^soc. Adv. Sci. 1883. Cf. Nature, xsix. (1883) p. 580. 

 X Comptes Rendus, xcvii. (1883) pp. 864-6. 



