MOLLUSCA. 427 



systemic veins are somewhat enlarged, and assume the ap- 

 pearance of auricles. The two pulmonary, or rather the 

 systemic veins, enter the heart at the opposite side, each 

 at the termination being furnished with a valvular orga- 

 nization. 



The systemic heart is white and fleshy, and differs ac- 

 cording to the genera in its form, being in the Octopus se- 

 micircular, but in the Loligo and Sepia lobed. Besides 

 giving rise to a large aorta, or principal artery, two smaller 

 ones likewise proceed from its cavity. These arteries are 

 furnished at their entrance with valves. 



The sexes in the Cephalopoda are distinct, the male and 

 female organs being found on different individuals. There 

 is not, however, any external mark by which they may be 

 distinguished. M. Cuvier found that the males of the 

 Octopus were scarcely a fifth part so numerous as the fe- 

 males. 



The male organs of generation consist of the following 

 parts : The testicle is a large white glandular purse, con- 

 taining numerous fringed filaments, from which the seminal 

 fluid is secreted. This fluid passes out of the testicle, by a 

 valvular opening, into the vas deferens. This canal is 

 slender, and greatly twisted in its course, and opens into a 

 cavity which has been compared to the seminal vesicle. 

 The walls of this last cavity are strong and muscular, and 

 disposed in ridges. Near the opening at the distal extre- 

 mity of this sac is an aperture leading into an oblong glan- 

 dular body, regarded as exercising the functions of a pros- 

 tate gland. Beyond this lies a muscular sac, divided at 

 the top, where it opens by two ducts, but connected at the 

 base. In this sac are numerous white thread-like bodies, 

 terminated by a filament, but imconnected with the sac. 

 In the interior they consist of a spiral body, connected at 

 each extremity with a glandular subhiancc. When these 



