CHAPTER VI 



WORMS 



Suggestions : — Earthworms may be found in the daytime after 

 a heavy rain, or by digging or turning over planks, logs, etc., in 

 damp places. They may be found on the surface at night by 

 searching with a lantern. Live specimens may be kept in the 

 laboratory in a box packed with damp (not wet) loam and dead 

 leaves. They may be fed on bits of fat meat, cabbage, onion, 

 etc., dropped on the surface. When studying live worms, they 

 should be allowed to crawl on damp paper or wood. An earth- 

 worm placed in a glass tube with rich, damp soil, may be watched 

 from day to day. 



External Features. — Is the body bilateral? Is there a 



dorsal and ^ventral surface? Can you show this by a test 



with live worm ? Do you know of an animal with dorsal 



and ventral surface, but not 



bilateral ? 



Can you make out a head ? 



A head end ? A neck ? Touch 

 Fig. 69. --AN Earthworm. th(J head an(J tesJ . whethcr ft 



can be made to crawl backwards. Which end is more 

 tapering ? Is the mouth at the tip of the head end or on 

 the upper or lower surface ? How is the vent situated ? 

 Its shape ? As the worm lies on a horizontal surface, is 

 the body anywhere flattened ? Are there any very distinct 

 divisions in the body ? Do you see any eyes ? 



Experiment to find whether the worm is sensitive (1) to touch, 

 (2) to light, (3) to strong odours, (4) to irritating liquids. Does it 

 show a sense of taste ? The experiments should show whether 



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