16 Moll. 
MOLLUSCA. 
7 . Nervous System. 
E. Heckel has studied the action of strychnine on some Gastropods ; 
Helix aspersa succumbed to '025 grammes of sulphate of strychnia, but 
Zonites algirus and Helix pomatia perfectly resisted doses of '045 grras., 
the weight of the snails themselves being only 6-9 grms. They enjoy, 
therefore, a remarkable immunity from the effects of that alkaloid. 
Specimens of small size are distinctly more sensible to it, and the action 
is finally tetanizing, as in other animals. O. R. Ixxxviii. pp. 918-921 ; 
abstract in J. R. Micr. Soc. ii. p. 705, and M. Journ. Sci. i. p. 514. 
Vulpian’s experiments with cardiac poisons on Helix pomatia show 
that their action is similar to that in the frog, the movement of the heart 
becoming irregular, and often ceasing for 5-6 minutes ; 0. R. Ixxxviii. 
p. 1293 ; abstract in J. R. Micr. Soc. ii. p. 857. 
Experiments on the respiratory innervation in Octopus ; L. Frj^dericq, 
0. R. Ixxxviii. pp. 346 & 347. 
The nervous system in the Clam, Mya arenaria, described and figured 
by A. S. Packard, jun., in “ Zoology for Students and General Readers,’’ 
(New York : 1879), pp. 246 & 247, figs. 165 & 166. 
8 . Organs of Sense. 
S. Richiardi states, as the result of numerous experiments, that the 
eye of Sepia officinalis is provided with a choroidea, iris, and true ciliar 
processes ; and that, therefore, the homology of the parts of the eye in the 
Oephalopods and Vertebrates is not as supposed by Hensen and others, 
as the front cover of the eye is not a cornea, but only a fold of the skin, 
extraordinarily developed in the Myopsidce in order to defend the eye 
against the pressure produced by retraction of the tentacular arms. 
Atti Soc. Tosc. 1879 ; abstract in Ann. N. H. (5) iii. pp. 243 & 244, and 
Zool. Anz. ii. pp. 138 & 139. 
An abstract of Schorl’s paper on the eye of the Oephalopods (Arch, 
mikr. Anat. xv. 1878), in J. R. Micr. Soc. ii. p. 705. 
Eyes of the Oephalopods discussed by E. Dorcum ; Am. Nat. xii. [1878] 
p. 591. 
Note on the eyes ot Patella; M. Braun, Tagebliitt d. 52, Versaml. 
deutsch. Naturf. 
An abstract of Claus’s paper on the auditory organ of the Heteropods 
(Arch mikr. Anat. xv. 1878, pp. 341-348), in J. R. Micr. Soc. ii. p. 401. 
Todaro describes the organ of taste in Pterotrachea, consisting of 
budlike prominences (bottom) of the epithelium in the oral cavity ; Atti 
Acc. Rom. (3) iii. Transunti, pp. 251 & 252. 
9 . Organs of Generation. 
Note on the sexual relations of some Mollusks; G. Canestrini, Bull. 
Soc. Veneto-Trent. i. p. 22. 
An abstract of Brock’s paper on the generative organs of the Cephalo- 
pods [Zool. Rec. xv, J\loll. p. llj, in J. R. Micr. Soc. ii. p. 549. 
