LUMBRICUS TERRESTRIS (An Earthworm). 



Phylum IX, ANNULATA; class i, CHJETOPODA; sub-class 2, OLI- 

 GOCH^ETA; order 2, LUMBRICOMORPHA. 



HABITAT. The Earthworm, or Angleworm, is found in all habitable 

 parts of the globe, any particular community having perhaps several 

 distinct species. It lives in burrows in the ground, coming out at night 

 or in damp weather to feed on leaves or other vegetable substances. 

 Its food also consists largely of organic matter in the soil which passes 

 through its alimentary tract as it extends its burrow. 



MOVEMENTS. Watch the movements of a live specimen placed 

 on a sheet of paper. Note the scratching sound as the worm crawls 

 about. What causes this sound? Observe the changes in length 

 and in the diameter of the cylindrical body. Is the progression for- 

 ward or backward? Look for pulsations in the blood-vessel which 

 shows through the dorsal wall. 



Technical Note. Place a preserved specimen on a sheet of white paper 

 pinned to the cork or wax in the bottom of a dissecting pan. Cover 

 with water and study with a hand lens. 



EXTERNAL FEATURES. Note the following relations and parts: 



a) An anterior and a posterior end, the former distinguished from the 



latter by its more rotund and tapering appearance. 



b) A dorsal surface darker hi color and more convex than the paler 



and flatter ventral surface. 



c) The body segments or metameres. Count them. They are 



somewhat longer near the anterior end than they are farther back. 



d) A rounded knob-like, lobe, the prostomium, projecting from the 



dorsal portion of the first segment or peristomium. 



e) The opening of the mouth just behind and below the prostomium. 



f) The anal segment the most posterior with its small median 



opening, the anal aperture. 



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