ANATOMY AND PHYSIOLOGY. 
Moll 37 
layer of unpigmented cylindrical cells ; the retina consists of elongated 
pigmented cells, with flask-shaped unpigmented cells lying between them; 
the pigment is peripheral, leaving an axial portion (“ rod ”) free; the 
colourless cells are probably epithelial in origin, and secrete the central 
jelly of the eye. The eye of Haliotis has a central cavity, and the gela¬ 
tinous plug is perforated by a fine canal; open eyes are also found in 
Troclius. In BEolis the eyes are small and irregularly spherical ; the 
inner wall consists of but few large cells, pigmented at the distal end, the 
cornea of small unpigmented cells; the author agrees in the main with 
Grenacher’s views on the Cephalopod eye. The so-called “eyes” in 
Cardium edule and Pinna are not such. The pupil of Pecten is dichroic, 
and the number of the eyes increases with the growth of the animal. A 
ring of ganglia is described around the rods from which a layer of separate 
ganglion cells, with long processes, passes to the central rods. A tapetum 
lucidum produces the metallic lustre of the eyes. In the second paper 
(67a) the eyes of Area noce and Pectunculus glycimeris are described ; they 
consist of a few broad cells, surrounded by pigment, and with a convex 
cornea; in the former, a thickening of the cuticle forms a lens ; the cells 
at the margin pass over gradually into those of the mantle. 
Some experiments on the sensitiveness of the olfactory sense in certain 
Pulmonata are given by Graber, Biol. Centralbl. v. pp. 387 & 456. 
See also Tafani (348). 
9 . Generative Organs . 
Rouzahd (316) traces the genital organs of hermaphrodite Gastro¬ 
pods to a “ primitive bud," arising at the back of the neck, which becomes 
afterwards club-shaped ; at its point of attachment to the body-wall 
there is afterwards formed either the common genital opening ( Helicklce ), 
or the female opening ( Limnceidce ) ; the distal extremity is embedded 
in the liver, and becomes the hermaphrodite organ. A “ penial bud ” 
arises near its base ; the club-shaped body separates into parallel cords, 
at first into two, the oviduct and vas deferens ; then the copulatory 
pouch is separated off. To these primitive structures all the various 
modifications of the sexual organs are traced. 
Genital apparatus of Nanina ( Xesia ) sibylla , Can., figured Jby Tappa- 
rone-Canefri, (66) fig. 9 ; that oiLimax brasiliensishy Jhering (202); 
that of H. quimyperiana, Fer., by Hesse (168), and of 5 species of Buli- 
minus, id. (169). 
Lacaze-Duthiers (227) replies to the last criticism of Fol (p. 26), 
stating that he has repeated his observations, and is convinced of the 
existence of a canal leading from the genital gland to the right kidney. 
Ashford (8) concludes his investigations into the dart-sac, and gives 
anatomical observations on some species which have no darts. Absence 
of a dart-sac and other peculiarities in the sexual organs of Helix sericea, 
Mull., noted by Ashford (7). 
Platxer (291) has examined the structure and movement of the sper¬ 
matozoa in many species ; a division into three was observed only in 
