I7O HUGH GLASGOW. 



PLATE VIII. 



These drawings, with the exception of Fig. 22, were all made from methylene 

 blue smear preparations direct from the caeca of the particular host insects given, 

 the purpose being merely to show the relative size and form of a few of the different 

 types of caecal bacteria. 



FIG. 21. Bacteria from caeca of Anasa tristis. Average size of individual rods 

 i by 0.7 micron. 



FIG. 22. Bouillon culture from caeca of Anasa tristis, several days old, showing 

 common involution forms regularly produced in this medium. 



FIG. 23. Bacteria from caeca of Blissus leucopterus. Average size of individual 

 rods, i by 0.8 micron. 



FIG. 24. Bacteria from caeca of Euschistus servus. Average size of rods, 4 by 

 0.9 micron, longest shown is 8 microns. 



FIG. 25. Bacteria from caeca of Peribalus limbolarhis. Size of rods, from 5 to 

 50 microns long by 1.2 microns. 



FIG. 26. Organism from Murgantia hislrionica.- Vary from 3 to 100 microns 

 long by i to 3 microns. 



