THE GRASSHOPBER 



25 



Remove one of the wing covers, being careful to get all 

 of it. 



How does its structure compare with the outer covering 

 of the body? Note the strong chitinous tubes running 

 lengthwise the wing and the smaller tubes running from one 

 to the other. How many principal veins do you find ? Note 

 that the wing is narrow, dense, and straight. 



Beginning with the lower edge of the wing, which is now 

 the front portion, find the large veins as follows : costal, the 

 vein nearest the margin, running about two-thirds of the 

 length of the wing; the subcostal, a very much larger vein 

 running nearly the entire length of the wing; the median, 

 much smaller and soon dividing into two veins nearly equal 

 in size ; the submedian and internal which run close together 

 to the outer margin of the wing. 



This divides the wing into three areas : the costal, the part 

 in front of the costal vein; the median, the largest, which 

 lies between the subcostal and the submedian veins; and 

 the internal, the part posterior to the internal vein. Find 

 and locate each. 



What seems to be the use of the outer wings? 



Make a sketch of the wing cover (X2). 



With the needle or tweezers pull out the inner wings to a 

 position at right angles to the body. How did the size 

 before stretching compare with the wing covers? How 

 does it compare after stretching? Count the number of 

 folds. How do they compare with the tegmina in structure 

 and texture? Do you find the costal, median, and internal 

 areas? How is the wing attached to the body? What 

 makes the inner wing fold up when the animal quits flying ? 

 Of what use is the inner wing ? Is the animal a good flyer ? 



