27 



Make a drawing of one of the cephalic legs. 



The same parts may be traced on each of the other legs. 



Wings. The wings are plate-like or membraneous ex- 

 pansions of the body-wall. Each wing is traversed by many 

 linear thickened portions ; these are termed veins or nerves. 

 The principal veins extend proximo-distad. These are joined 

 together by many smaller cross-veins. The thin parts cir- 

 cumscribed by the veins and cross-veins are called cells. 



The two pairs of wings of a locust differ remarkably in 

 form and texture. 



Mesothoracic wings (tegmina}. The mesothoracic wings are 

 long, narrow, and of a parchment-like texture. They are 

 termed tegmina. 



Metathoracic wings. The metathoracic wings are much 

 larger and of more delicate texture than the first pair of 

 wings. When not in use they are folded in plaits like a fan 

 and concealed by the tegmina. Some writers who designate 

 the mesothoracic wings as tegmina or wing-covers, describe 

 the metathoracic wings simply as the wings. 



PARTS OF THE ABDOMEN. 



Number of segments There is a difference of opinion 

 as to the number of segments in the body of a locust. The 

 difficulty arises from the complexity of the caudal end of 

 this region, and the fact that some authors have considered 

 the first abdominal sternum as a part of the metathorax. 

 Eight abdominal segments can be readily distinguished in 

 the female , and nine, in the male.* Caudad of the eighth 

 abdominal segment of the female and the ninth of the male 



* If a sufficiently large series of specimens of the red-legged locusts be exam- 

 ined it will be seen that there are two kinds , one, in which the caudal part of 

 the body tapers to the end, and bears four, pointed find curved, horny pieces ; 

 and another, in which the caudal part of the body increases in size caudad 

 and is terminated by a single, large, hood-shaped plate. The former is the 

 female , the latter, the male. 



