PLATE XXVI 



Figure 1. A villus of the mid-gut of Tabanus, immediately after 

 the first meal of blood. The deeper cells are highly 

 vacuolated, while the ones nearer the lumen are dis- 

 charging their contents into it, and are disintegrating. 



Figure 2. A section through the same gut, at a lower level, and 

 nearer the centre. The dark area on the right of the 

 drawing is blood pigment, derived from the digestion 

 of the layer of blood which has been in contact with 

 the epithelium. The rest of the lumen is filled up 

 with disintegrating cells, loaded with granules. In 

 some the nucleus, in varying stages of disintegration, 

 persists. In others there are large vacuoles. In the 

 spaces between the cells there is a quantity of granu- 

 lar matter derived from the breaking down of cells. 



