LIST OF PLATES. 



PLATE 



I. Glossina palpalis, Robineau-Desvoidy. {6 ■ X 6) 



II. Glossina caliginea, Austen. ( $ . x C) . 



III. Glossina jjallicera, Bigot. (6- X 6) 



IV. Glossina tachinoides, Westwood. ( 9 . X 6) 

 V. Glossina morsitans, Westwood. ( 9 • x G) 



VI. Glossina pallidipes, ka.'s.ten. (9. x 6) . 

 VII. Glossina longipalpis, Wiedemann. {S . X 6) 

 VIII. Glossina fusca, Walker. ( 9 . X 6) 

 IX. Glossina hrevipalpis, Newstead. {$ . x G) . 

 X. Glossina longipennis, Corti. ( 9 • x G) . 



Map of Africa south of the Sahara, illustrating the distri 

 bution of Glossina ...... 



Frontispiece 

 At end 



facing page 8 



Note. — The crossed lines indicate the natural size (length and wing- 

 expanse) ; the vertical line includes the palpi. 



Students who are not trained entomologists sometimes find it difficult 

 to realise the natural size and appearance of an insect from a greatly 

 enlarged figure. By viewing such a figure through a pocket lens, held at 

 a distance from the object considerably greater than the focal length for 

 magnification, and also at a distance from the eye, there can be obtained 

 a reduced image of the illustration, which can be made to approximate 

 very closely to the natural size of the insect. The desired result will be 

 facilitated if the length of the cross-line indicating the wing expanse, 

 and that of the line representing the length of the fly, be first compared 

 with the diameter of the lens ; before being examined in this way, a 

 figure should, of course, be inverted. 



