CHAPTER IV. 



Bkakch IV.— Vermes (Worms). 



General Charactees of Worms.— In order to obtain 

 an idea of worms in general the student may dig up in the 

 garden or fields a common earth-worm, and then place it on 

 the table or desk in a flat dish and watch its movements 



Fig. 37. —Transverse section through the body of the eaxth-woria ( LumbHcus ter- 

 restris), near the middle of tlie intestine- a. cuticle; b, hypodermis; c. circu- 

 lar layer of muscles; d, layer of longitudinal muscles; e, dorsal band; /, ven- 

 tral band; fir, lateral bands; h, typhlosole; ;'. caviry of intestine; ./, epithelium 

 of intestine; k, layer of circular-muscular fibi'es around intesti.ie; (, layer of 

 longitudinal muscular fibres around intestine; m, green layer on outer sur- 

 face of intestine; n, heart; o, liver; ng, nervous ganglion After Clapar6de. 



and appearance. The body will be seen to be formed of 

 numerous joints or segments; these are due to infold- 

 ings of the muscular skin at regular intervals. Though 

 both ends of the long, slender, cylindrical body are much 



