252 ANNULATA 



MORPHOPHYSIOLOGIC STUDY 



A. External Morphology 



1. Shape? Use of this shape to the animal? 



2. Size. 



(1) Length of earthworm when quiet? When extended? 



(2) Thickness laterally? Dorsoventrally? 



(3) How^ does the thickness compare with the length? 



3. Covering. Is the skin naked or covered? If covered, 

 with what? 



4. Surfaces. 



(1) Shape and color of the dorsal surface? Use? 



(2) Shape and color of vental surface? 



(3) Do these surfaces differ in shape and color? If so, why? 



5. Somites or Segments. 

 (1) Number? 



, (2) Are they similar in different regions? Why? 



6. Cingulum, Girdle, or Clitellum — a swollen region near the 

 anterior end. 



(1) Over how many somites does it extend? 



(2) Does it extend entirely around the body? 



(3) Use to the earthworm? 



7. Setse or Feet on ventral side. Use hand lens or feel them 

 along the ventral surface. 



(1) How many to each somite? 



(2) Upon how many somites are they found? 



(3) How many rows in all? 



(4) How many setae on the entire earthworm? 



(5) Use of these setse? 



8. Openings in the Body Wall. Identify as many as you can 

 with the hand lens. 



(1) Mouth at anterior end. 



(2) Vent at posterior end. 



(3) Seminal receptacles. Look for them with hand lens 



about the 9th-llth somites. 



(4) Oviducts. Look for them about the 9th somite. 



(5) Vas deferens, about the 15th somite. 



(6) Dorsal pores — along the dorsal surface. 



(7) Nephridial openings — one pair to each somite. 



