— 45 — 



On each side of the heart and ectad of the wings of the 

 heart, there are great bands of longitudinal muscles, occupy- 

 ing the space between the heart and the prominent muscles 

 that extend dorso-ventrad on the sides of the body. Of the 

 longitudinal, dorsal muscles there are two sets on each side. 

 The wider set, which lie near the heart, may be termed the 

 great-dorsal-redi-muscles ; the narrower set, which lie be 

 tween the great-dorsal-recti -muscles and the dorso- ventral 

 muscles of the sides of the body, may be termed the small- 

 dorsal-recti-m uscles. 



Of the dorso- ventral muscles of the sides of the body, re- 

 ferred to above, there are two large bundles on each side of 

 each segment ; they are situated near the union of the seg- 

 ments. 



Between the lateral muscles and the cut edge of the speci- 

 men (the dorsimeson) lie the great-ventral-recti-muscles . 

 These differ from the great-dorsal-recti-muscles in' being 

 somewhat oblique (this is shown better in specimens opened 

 on the dorsimeson). 



Make a drawing of the third, fourth, and fifth abdominal 

 segments respresenting the muscles mentioned above and 

 the heart and its wing-muscles. 



Carefully remove the recti muscles in one or two abdomi- 

 nal segments and note that ectad of them are many muscles 

 extending obliquely in various directions. The study of 

 these oblique muscles will be omitted in this course. 



Examine Plates VI, VII, VIII, XV, XVI, and XVII, of 

 the "Traite Anatomique de la Chenille" of Lyonet and 

 Plates III and IV of the "Considerations Gfneralcs sur 

 V Anatomie Comparee des Animaux Articulis" by Straus- 

 Durckheim. 



