XII 



PHYLUM MOLLUSC A 



their posterior junction is given off a median diverticulum 

 (Fig. 671, med. s), into which the pancreatic follicles (pane.) project. 

 Through each excretory sac runs the corresponding afferent 

 branchial vein, formed by the bifurcation of the vena cava, 

 and surrounding it are masses of glandular tissue (Fig. 670, 

 ven. app), by whose agency the process of renal excretion (the 

 products of which, in the shape of a nitrogenous excretory 



jned.s 



abd.i> 



inh.s.f 



Fir,, r.70.— Sepia officinalis, excretory organs. aJ>d. v. abdominal vein ; ap\ funnel-like opening 

 from the pericardium ; a>>2, aperture of communication between the left and the median 

 nephridial sac ; ink: *. v. ink-sac vein ; mal. s. median sac ; pall, v. pallial vein ; ur. ureter ; 

 t, Mm vena cava ; ren. app. venous appendages of the afferent branchial veins. (From Vogt 

 and Jung, after Grobben.) 



substance called guanin, are to be detected in the internal cavity) 

 is carried on. 



Reproductive system. — In the male the testis (Fig. 672, te.) 

 forms a compact mass of minute tubules situated in the aboral 

 region of the body and enclosed in a capsule. The single spermi- 

 duct (v. def) is a greatly convoluted tube which leads from the 

 cavity of the capsule towards the right ; it opens into an elon- 

 gated veaicula seminalis (ves.), to which is appended a glandular 

 body, the prostate (pr.). In the interior of the vesicula seminalis 



