A MANUAL or ZOOLOGY 33 



it entaBKhe liver. A delicate duct will be found leading 

 fromytH^liver to the spleeii and on to the stomach, on 

 eith^ljide of the oesophagus as it enters the liver, hepatic 

 ducfllUPescribe the liver as to location, size, shape, and 

 color. Now trace the aorta and the oesophagus through 

 thinner and from there to the head. Watch tor the sali- 

 vary glands on the dorsal' surface of the anterior end of- 

 the liver. Make a drawing nf \]\p. j ^jpr ritivn npirrrTfTF" 



REPROihfeTiVEf'ORGA;^S— The testis or ovary ac- 

 cording to sex, is a white dense mass under the stomach 

 on the median line and extends posteriorly. Notice the 

 acc'essory reproductive organ at the left. Notice on the 

 left Ventral arm of the male that the acetabula are modi- 

 fied so that the stalks are prolonged into blunt points. 

 Compare these with those of the female. 



No duct joins the testis with the vas deferens. There- 

 fore the ripe spermatozoa pass through the cavity of the 

 capsules into the excretory duct. ' ' ' 



The' reproductive organs of the female comprise the 

 ovary, oviduct, gland of the oviduct, hidamental glands, 

 and accessory nidameiital glands." 



Find the hidamental glands, upon opening the mantlg, 

 cavity, in the" region of the heart, as white laminated 

 bodies. The capsules of the egg masses are excreted by 

 these. The accessory gland's are found in the region 'of 

 the ink sac. , T 



Look for the ovary in similar po'sitirii as 'the testis 

 of the "male. The eggs escape from the capsule to be 

 taken up by the oviduct. The oviduct, a loilg thick-walled 

 tube, passes along the left side and opens in the region 

 of the siphon. ' ,...,,,,,' 



The oviduct may be trafced to a point below the left 

 gill into the large oviducal gland, at the left of the poster- 

 ior end of the nidainental glan^i' libok for eggs in varying 

 stages. of deveiopment in the ovary. 



Carefully take away all the "organs of the /Wdy cavity, 

 turn the animal uPon the ventral side, and cut through 

 the integuBient along tj^e mid-dorsal line. , An elongated 

 cartilaginous pen will be found here, Tgkejt_pu t oarofully 

 and mg.kft a drawin g of it desc ribiy ^ 4 in '"fovfi'g an wp'II^ 

 Does this pen suggest in any way, aah^U? ^s the pen 



