Chapter XI 



INTERNAL ANATOMY OF MOSQUITOES 



THE ALIMENTARY CANAL 



The alimentary canal is specialized on account 

 of the blood-sucking habits of the mosquito. It 

 differs from many insects in not possessing any caecal 

 diverticula of the mid-gut. It also differs in the 

 possession of five malpighian tubules, these being in 

 insects usually even in number (Fig. 38). 



The parts of the alimentary canal are as follows : 

 The mouth \ 



The pharynx with pumping organ | The fore- 

 The oesophagus j gut. 



The oesophageal diverticula J 



The homologue of the proventriculus jrp, ._. 

 The stomach (so-called) 



The pylorus j gu1 



The pyloric dilatation \ 



The ileum I The hind- 



The colon gut. 



The rectum with rectal papillae j 



The mouth, pharynx, and oesophagus are ecto- 

 dermal in origin, and both the mouth and pharynx 

 are lined with chitin. The hind-gut is also ectodermal 

 in origin ; it does not possess, however, any portion 

 lined with chitin. The mid-gut is the true digestive 

 portion of the tract. 



