64 



R. NEWSTEAD THE PAPATACI FLIES (PHLEBOTOMUS) 



The sucking stomach. This is a large, tliin-walled pouch, connected with the 

 end of the oesophagus by means of a very slender tube. It lies on the left side 

 of the digcstii-e canal, and extends distally as far as the region of the fourth 

 abdominal segment. 



The mid-gut or chyle stomach. This is capable of great distention, and when 

 filled with fresh blood occupies a large portion of the abdominal cavity ; but 

 when such food has been partly comminuted it becomes much smaller, and can be 

 easily seen as a black, elongated pouch in the anterior portion of the body. 



Malpighian tubules. There are two paii'S of urinary oi'gans, each pair being 

 united at their bases, where they form a single tube, which is connected with the 

 intestine immediately below the mid-gut. They are of great length, extending 

 forwards as far as the first abdominal segment, where they are folded and 

 doubled backwards upon themselves, and also form loops in the mid-region of the 

 ventral portion of the abdominal cavity. 



The salirary glands (fig. 9). These consist of two broadly dilated or lobe-like 

 acinous glands, lying one upon either side of the prothorax. The periphery of 



fenna 



Fig. 9.— Head of Phhhoto 



Salivary 

 duct 



Salivary 

 gland 



showing position of salivary glands. 



these glands presents an even or smooth surface, and immediately within the 

 exterior wall is a series of rather large secretory cells. The ducts leading from 

 the acini unite near the mid-region of the head, forming a common duct, which 

 enters the buccal cavity close to the base of the clypeus. 



The Sexual Organs of the Female. 



The ovaries occupy a variable position in the different stages of their 

 development. In the early adult stages of the insect (fig. 8) they are very small, 

 and are seen to extend from just behind the origin of the JVJalpighian tubules to 

 the region of the penultimate segment of the abdomen. When fully matured 





