PHERETIMA. 



108. Viscera. Pin the worm ventral surface downwards by two pins through the 

 sides of segment 4. Stretch the body and pin down the posterior end. Open the body- 

 wall from segment 35 to the anterior end by cutting with scissors slightly to one side of the 

 mid-dorsal line, taking great care not to cut the dorsal blood-vessel. Pin out the body- 

 wall on either side, arranging the pins to mark segments 8, 12, 16, 20, etc. Draw your 

 dissection, showing : coelom ; septa ; alimentary canal, consisting of buccal region, 

 pharynx, oesophagus, gizzard, intestine with caeca in segment 26, chloragogen cells ; supra - 

 pharyngeal ganglia ; dorsal blood-vessel ; four pairs of pseudo-hearts (segments 10-13) ; 

 two pairs of vesiculaa seminales (segments 10 and 11) ; one pair of spermiducal glands 

 (segment 18) ; two pairs of spermathecae with diverticula (segments 6 and 7). 



109. Blood System. Make a diagram of the lateral aspect of the blood system 

 showing: dorsal vessel; pseudo-hearts; sub-inteatinal vessel; sub-neural vessel; parietal, 

 oesophageal and intestinal vessels. 



