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The Internal Anatomy of Stomoxys. 

 By F. Tulloch, Lieut. E.A.M. Corps. 



(Communicated by Professor E. Ray Lankester, F.E.S. Received February 2, — 



Read March 1, 1906.) 



The dissections of the local variety of Stomoxys, which form the subject of 

 this Note, were made at the suggestion of Professor Minchin, during his 

 direction of the Royal Society's Commission on Sleeping Sickness in Entebbe, 

 Uganda. The main object was to furnish some comparison between the 

 internal anatomy of Stomoxys and that of Glossina, and the following notes 

 are based on Professor Minchin's description of Glossina palpalis. 



Complete digestion of the human trypanosome seems to occur in 48 hours, 

 in the alimentary canal of Stomoxys ; but Lieutenant Gray, R.A.M.C., 

 has found a limited percentage of these Stomoxys to be infected with a 

 Herpetomonas. 



I am much indebted to Professor Minchin for advice and assistance at 

 every turn, without which these notes could not have been completed. 



Digestive System. 



The cesophagus emerges from the chitinous pharynx (which, with the 

 mouth parts, has been described by Hansen) as a flattened tube, which 

 gradually narrows and becomes cylindrical, running at first upwards and 

 then backwards to reach the brain. The connectives of the brain are more 

 vertical than in Glossina. On emerging from their constriction the 

 cesophagus dilates gradually, and runs down to enter the ventral aspect of 

 the proventriculus, which lies in the anterior third of the thorax. 



The proventriculus (fig. 1, P.) is a mushroom-shaped viscus with a 

 thickened border, and lies with its convexity pointing upwards and slightly 

 forwards. Except for the inversion of its lateral edges, which gives to the 

 proventriculus of Glossina a characteristic outline, the corresponding structure 

 in Stomoxys is very similar in every way. The oesophagus enters the 

 proventriculus a little in front of the centre of its concave ventral surface, 

 and the duct of the sucking stomach running up from below appears to enter 

 with it, though in reality it enters separately at a point immediately behind. 

 As in Glossina, the oesophagus and the duct of the sucking stomach are 

 in the same line. 



The thoracic intestine (fig. 1, T.I.) arises from the convex dorsal surface of 

 the proventriculus at a point posterior to the entrance of the oesophagus on 



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