DISSECTION OF GRASSHOPPER. 175 



enlargements (ganglia) in this ? How are they arranged 

 with regard to the somites ? Follow the nervous system for- 

 ward, if possible, into the head. Can you find cords pass- 

 ing around the oesophagus as in the crayfish ? Is there a 

 brain above the gullet ? Does the alimentary canal pass 

 through the nervous system ? 



Draw a diagram of a section passing through the thorax, 

 showing the body-wall, wings, legs, spiracles, egg-masses, 

 nervous cord, alimentary canal, and heart-in their relative 

 positions. 



