332 



FRANCIS O. HOLMES. 



LOCALIZATION IN DORSAL AND ANTERIOR LOBES. 



It was in the third or dorsal lobe that the flagellates were 

 really abundant. There they were often massed like a new 

 tissue lining the entire lumen of the gland. The dark stain 

 which the fluid took made it difficult to study the internal 

 structure of the organisms. Yet they were so abundant that 

 some were usually favorably located for observation. The 

 flagellates lined the dorsal lobe most heavily near its posterior 

 extremity. Nearer the efferent duct the organisms were often 

 in groups or clusters, isolated a little from the rest of the mass, 

 but closely bunched together with flagella attached to the 

 wall. 



In the anterior, foam-filled lobe there were a few flagellates 

 always when they were present in the dorsal lobe. In the 

 posterior lobe there were none, no matter how heavily the insect 

 was parasitized. 



FIG. 3. Portion of a longitudinal section through Oncopeltus, showing the 

 relative positions of the salivary gland and other thoracic organs. The three 

 lobes of the gland come together in this particular section and the point of entrance 

 of the salivary duct is shown. 



That the fluids from the three lobes intermingled slightly at 

 the common point of contact where the three fluids drained into 

 the same efferent duct was indicated by the mixed consistencies 

 and colors just at this exit point. In the smooth orange-red 

 fluid a cloud of pink was always seen to have penetrated for a 



