126 ELEMENTS Off COMPARATIVE ZOOLOGY. 



(25) Is the aorta dorsal or ventral to alimentary canal ? 



(26) What vessels carry blood to the head ? 



(27) Are the respiratory organs connected, either directly 

 or indirectly with the alimentary canal ? 



(28) Are any parts (if so, what) repeated one after an- 

 other in the body ? 



(29) Draw a diagram of a transverse section through the 

 body in the region of the heart, showing the heart, spinal 

 cord, oesophagus, vertebra, aorta, and body-walls. 



(30) Draw a similar section through the kidneys, show- 

 ing the peritoneal cavity, intestine, mesentery, spinal cord, 

 kidneys, aorta, vertebra, etc., and the body-walls. 



