32 Mull. 
MOLLUSCA. 
along the border of the gill, and also along each lamina. In the adult a 
foramen is seen between the bases of each pair of gill laminae, small in 
Sepia , but large in Ommastrephes , and still larger in the Octopods, form¬ 
ing a canal through which passes the current of water. .In Sepia each 
lamina is triangular, the angles at the base being occupied by the main 
efferent and afferent vessels; the latter gives off two branches to each 
lamina, one much smaller than the other, this inequality being less in 
Ommastrephes ; the minute branches in the folded laminae are so dis¬ 
posed that the afferent vessels occupy the highest and lowest points of 
the folds, while the corresponding efferent vessels lie between them. 
The surface occupied by these lamellae is calculated at 900 sq. cm. for 
each gill. A system for the nourishment of the gill itself is formed by 
a small vessel given off by the afferent vessel at the base of each lamina, 
the blood being collected into a vein which runs down the gill parallel to 
the afferent vessel. Furthermore, a connection takes place between the 
extremities of these nutrient vessels and those of the veins from the 
branchial gland. This latter is compared with a spleen, as it has no duct 
and receives blood which has circulated in another organ (the gill). The 
branchia of the adult Octopods ( Octopus , Eledone , Argonauta ) is described 
in some detail, and compared with that of the Decapods. 
6 . Excretory and. Secretory Systems. 
Girod’s paper on the ink-bag of Cephalopods abstracted ; Ann. Soc. 
mal. Belg. xix. pp. xi.-xiii. [see Zool. Rec. xix. Moll. p. 15]. 
Hammarsten (Arch. ges. Phys. xxxvi. pp. 384-456) finds that the 
mantle of Helix pomatia excretes mucin, as also does the foot. The liver 
contains 1 *75 percent, of ordinary glycogen ; in animals which had hiber¬ 
nated in a warm room the liver contained 0*429 per cent, of glycogen. 
Barfurth (12) has investigated the presence of glycogen in Helix, 
Limax, A rion, and Cyclostoma, where he found it in most of the organs. 
The quantity in the muscles is inversely proportional to their activity ; 
the plasma-cells of Brock contain it in the greatest abundance. Three 
weeks’ fasting causes it to disappear from the liver, but it reappears nine 
or ten hours after feeding. Claude Bernard’s division of the Gastropod 
liver into a bile- and a glycogen-forming organ must be abandoned; 
physiologically as well as developmentally it is a part of the gut. Gly¬ 
cogen is formed in the salivary glands only some time after feeding, disap¬ 
pearing shortly. In Helix no cilia were found in the salivary ducts. 
Hepatic epithelium consists of liver-, ferment-, and calcareous-cells. 
Glycogen has been found by Blundstone (24) in large vesicular cells in 
the mantle of Anodon and the mesentery of Helix. 
According to Schuler (329), the spaces in the foot of Anodonta are 
not lacunae, but cells with clear mucoid contents. 
Action of Molluscan kidney discussed by Landsberg (228), who 
comes to the conclusion that the “canal between the pericardium and 
kidney serves only to transmit from the former to the latter the fluids 
which have been expressed through the cardiac walls.” 
Haller (156) gives a detailed account of the kidney of Fissurella , 
