88 INSECTA 



(b) Labial palpi. Look on each side of the sucking tube 

 for the jointed appendage. 



(1) How many segments? 



(2) Are the palpi naked or hairy? 

 3. The Thorax. 



(1) How does it differ from the thorax of the grasshopper? 



Fig. 4. — Ideal transverse section of an insect : h, Dorsal vessel ; i, intes- 

 tine; n, ventral nerve-cord; 1 1, stigmata leading into the branched tracheal 

 tubes; ww, wings; a, coxa of one leg; b, trochanter; c, femur; d, tibia; e, 

 tarsus. (After Packard.) 



(2) The Wings. 



(a) Number? 



(b) Location? 



(c) Color above? Below? 



(d) Any differences between anterior and posterior wings? 



If so, what? 



(e) How folded when at rest? 



(f) Covered with scales, naked, or hairy? Place a por- 



tion of a wing under the microscope, and draw 

 several scales. Do you find any transparent spots 

 where the scales have rubbed off? 



