38 SEXUAL ORGANS. 



be startled by the sudden appearance of masses of dar^ color in 

 the water, and in the confusion the cuttle makes his escape __ 

 W. R. HUGHES, in Nature, ix, 363, 1874. 



Dorsal aquiferous pores are found opening upon the head in 

 Argonauta and Tremoctopus : they communicate with large 

 internal cavities. In Ommastrephes and Tremoctopus anal pores, 

 with small cavities, are found on each side of the siphon ; in 

 Onychoteuthis they are placed in advance of it ; in other genera 

 they are wanting. The buccal region in Histioteuthis and Om- 

 mastrephes has four aquiferous pores, and there are six of them 

 in Onychoteuthis, in Sepia and in Loligo: the other genera want 

 them. Finalty, there are brachial pores situated near the bases 

 of the tentacular arms and between the third and fourth pairs of 

 sessile arms : in Sepia, Sepiola and Rossia they communicate 

 with the great cavities in which are lodged the tentacles when 

 contracted ; in Loligo the smaller cavity only suffices to lodge a 

 portion of the tentacula, and in Histioteuthis, Ommastrephes 

 and Onychoteuthis the cavity is still more restricted, and only 

 occupies a part of the head anterior to the eyes : wanting in 

 other genera. These pores are probably lubricative in function. 



ftc.rual 



The sexes are distinct in the cephalopoda und in some of the 

 genera at least, the female individual is the largest and readily 

 distinguishable externally. The reproductive organs are lamellar 

 or branched; their cellular contents arc metamorphosed into ova 

 or spermatozoa, which are attached to the wall of a chamber 

 communicating with the pallial cavity by one or two ducts, which, 

 in the female present glandular enlargements, rpon the walls 

 of the branchial cavity of the female two nidiniental glands are 

 developed ; besides, sometimes accessory glands, within which is 

 secreted a viscid lluid which envelops the ova and au'lii'd' 

 them into various forms, differing Mi-cording to the "vims. 



In the male the cases or spermafophores containing the sper- 

 mato/oa are furnished by a prostatic gljnid. These spermato- 

 phores. in the diliranchiata are ovate, cylindrical and narrow, 

 consisting of a thin case, ending sometimes in a filament at one 

 end; at the other or thicker end is contained a sack full of 

 spermatozoa, to which is attached an elastic spiral cord, coiled 



