14 Molh 
MOLLUSCA. 
& 929. Critical note on these statements, and some original observa- 
tions, statihg that curare acts much more powerfully on Gastropods than 
on Cephalopoda and Heteropods, and almost not at all on Bivalves, by 
C. r. Kkukenbeiig, Vergl. physiol. Studien, i. pp. 35, 117-123, hi. p. 178, 
footnote. 
Helix pomatia perishes in an atmosphere filled with camphor after three 
hours; Kkukenberg, op. cit. i. p. 95. Strychnine has no serious influence 
on this snail ; id. 1. c. p. 100. 
See also Cephalopoda^ Chromatophores. 
8 . Organs of Sense, 
Eyes of Pecten maximuSy jacohceus, and operculariSy described by S. J. 
Hickson, Q. J. Micr. Sci. xx. pp. 443-455 ; abstract in J. R. Micr. Soc. 
(2) i. p. 230. Their number varies in different individuals from 80 to 120. 
The lens is multicellular, there is a highly developed tapetum, and the 
optic nerve, passing up the side of the eye-cup, bends over, and spreads 
itself over the anterior surface of the retina, behind which the pigment 
is situated. They have, therefore, more likeness to the eyes of the Verte- 
hrata than those of any other Inverteiratay even Onchidium, but their 
development must of course be essentially different. Their functions 
appear to bo very limited. 
Organ of Smell. D. SociiiEZEWER discusses the question of the seat 
of smell in land snails. He proves by experiments with oil of turpentine 
that it is not in the feelers, as La Pluche (1772), Moquin-Tandon, and 
Velten supposed, but near the mouth. The so-called organ of Semper 
at the entrance of the mouth is essentially of glandular structure, and 
contains no sensitive cells, but the pedal gland, which is opened beneath 
the mouth and secretes slime, contains conspicuous sensitive cells in its 
epithelium, which are described and figured by the author, and he thinks 
therefore, with Deshayes and Leidy, that probably this gland is the seat 
of smell. His researches have been made chiefly in Limax cinereo-niger, 
Z. wiss. Zool. XXXV. pp. 30-46, pi. iii. ; abstract in J. R. Micr. Soc. (2) i. 
p. 24. 
Peculiarly fine furrows, arranged in two lines on the lateral parts of 
the body and more intensely coloured in Doridium, and analogous wart- 
like prominences on both sides of a common axis in Bulla hydatis^ ate 
regarded as the organ of smell by Vayssiere, Ann. Sci. Nat. (G) ix. 
Art. 1, pp. 110 &. 111. 
J. W. Spengel states the existence of a peculiar sensitive organ in the 
mantle cavity of most Mollusca, near the gills, which he thinks to be the 
seat of the sense of smell. It has been described by former authors as 
a rudimentary gill or a ciliferous prominence ; Gegenbaur alone suspected 
in the Pteropoda its sensory and especially olfactory nature. It has 
been found also in the Bivalves. Z. wiss. Zool. xxxv. pp. 373-381, 
pis. xviii. & xix. 
Abstract of Todaro’s paper on the gustal organ in Pterotrachea [Zool. 
Rec. xvi. Moll. p. 16] in Arch. Z. exp(^r. viii. p. 1., and in J. R. Micr. Soc. 
(2) i. p. 228. 
