PLATE XXVII 



Figure 1. The nervous system of Tabanus. br., brain. a.n., 

 antennal nerve. o.l., optic lobe. n.t., nerve trunk, 

 formed from two branches which emerge from the 

 suboesophageal ganglion. t.g., thoracic ganglion, 

 ab.g., abdominal ganglia. X 140. 



Figure 2. Pericardial cells from Haematopota. x 500. 



Figure 3. Fat body from a newly hatched Philaeniatomyia, 

 eo., compact homogeneous particles which stain 

 brightly with eosin. v., vacuoles. n., nucleus. 



Figure 4. The compound thoracic ganglion of Mnsca domestica. 

 After Gordon Hewitt. 



Figure 5. Cross-section of the salivary gland of Haematopota. 

 x 400. 



Figure 6. Longitudinal section through the salivary gland of 

 Culex. sl.d., the salivary duct. X 800. 



Figure 7. The salivary gland of Culex fatigans. 



Figure 8. The salivary gland of A nopheles rossii. 



Figure 9. One salivary gland of Tabanus albimedius. X 30. 



Figure 10. Cells of the labial salivary gland of Haematopota. 

 These are similar to those in Musca, and to those of 

 Philaematomyia, in which, however, the permanent 

 vacuole is not so well seen, n., large nucleus, n'., 

 small nucleus at the opposite end of the cell, v., 

 vacuole. x 650. 



Figure 11. Scheme of the circulatory system, h., heart, p.c., 

 pericardial cell, t., tergite. al.m., alary muscle : the 

 tendons spread out in the middle line, and form a wide 

 sheet perforated in places, ha., haematocoele. ov., 

 ovaries, al.t., alimentary tract. st. sternite. The 

 arrows indicate the direction of the flow of the blood, 

 through the interstices between the fat body and the 

 organs, into the pericardial chamber and the heart, 

 within which it is propelled forwards through the 

 to the head. 



