78 



TEXT-BOOK OF ENTOMOLOGY 



In the Diptera the hypopharynx reaches its highest development 

 as a large, stout, awl-like structure. 



Meinert, in his detailed and elaborately illustrated work, Trophi 

 Dipterorum (1881), has made an advance on our knowledge of the 



sm 



Ibr 



rnx.p 



nix 



FIG. 81. Cultfx pipiens, section of head : oe, oesophagus ; $m, upper muscle, Im, lower mus- 

 cle of the oesophagus ; ph, pharynx ; rm, retractor muscle of the receptacle (r) of the salivary duct 

 (n.d) ; Ibr, labrum ; ep, left style of the epipharynx ; ,/, part of front of head. After Meinert. 



hypopharynx and its homologies, both by his evidently faithful de- 

 scriptions and dissections, and by his admirably clear figures. 



"The hypopharynx, a continuation of the lower 

 edge (lamina) of the pharynx, most generally free, 

 more or less produced, acute anteriorly, forms with 

 the labrum the tube of the pump (antlice). (The hypo- 

 pharynx when obsolete, or coalesced with the canal of 

 the proboscis, is the theca ; in such a case the siphon 

 or tube is formed by the theca and labrum.) Mean- 

 while the hypopharynx, the largest of all the trophi 

 (omnium trophorum maximus), constitutes the chief 

 piercing organ (telum} of Diptera. The hypopharynx 

 is moved by protractor, most generally quite or very 

 powerful, and by retractor muscles. 



"The efferent duct of the thoracic salivary glands 

 (fliictus salivalis) perforates the hypopharynx, more 

 or less near the base, that the saliva may be ejected 

 through the canal into the wound, or that it may be 

 conducted along the labella. Very rarely the salivary 

 duct, perforating the hypopharynx, is continued in 

 the shape of a free, very slender tube. 



The salivary duct behind the base of the hypo- 



m 



FIG. 82. Pharynx and 

 livpopliaryiix of Shu uli mn 

 f'ltxi-i/H'N : hili, lower lamina 



of UK- pharynx ; />. the >aii- pharynx forms the receptacle or receptaculum, provided 



vary <lurt (s.d) pn-f.-nitin}.' w i t h retractor and levator muscles." 

 the pharynx ; <>, orifice ol 



the' clnct ; x/i/i, styles of the 

 hvpopharyiix ; inji/i, mem- 

 hnmoiis e<lf, r c of the livpo- 



. 

 After 



It has been carefully studied by Meinert in 

 V.iVarvnx; a species of Culex (Fig. 81), Siuiulium (Fig. 



papilla.. - 82 ^ Tabanug ( Fig 33^ and in Agilus ( Figi 84 ) ? 



