PLATE 2 
Fig. A to J.—Cross sections of portions of the alimentary canals and Malpighian 
tubtiles of worker honeybees, showing “precipitated” indigo-carmine that had been 
fed with pure nicotine and honey to bees three days before they were fixed in abso¬ 
lute alcohol. Owing to poor fixation, most of cells are drawn diagrammatically. 
Fig. A.—Portion of the wall of the ventriculus, showing the “precipitate” pr 
in inner ends of the epithelial cells ep. X320. 
Fig. B.—Portion of the wall of the ventriculus, showing the “precipitate” 
pr in the middle of the epithelial cells ep. X320. 
Fig. C.—Portion of the wall of the ventriculus, showing the “precipitate” 
in the outer ends of the epithelial cells ep and in the transverse muscle layer 
tm. X320. 
Fig. D.—Portion of the wall of the honey stomach joining the proven- 
triculus, showing the “precipitate” pr in the chitinous chi and muscular m 
layers. X320. 
Fig. E.—Portion of the wall of the anterior part of the valve of the proven- 
triculus, showing the tl precipitate” pr in muscles m , tracheae tr, and epithelial 
cells ep. X320. 
Fig. F.—Section through the small intestine, showing the “precipitate” pr 
in the center of the lumen l and lining epithelium ep, but none in the walls of 
this organ nor in the Malpighian tubules mal by it. X 50. 
Fig. G.—Section through two Malpighian tubules mal against the ventriculus, 
showing the “ precipitate ” pr in their cells and lumens l. X320. 
Fig. H. —Section through two Malpighian tubules mal near the ventricu¬ 
lus, tracheal branch tr and blood bl, showing the “precipitate” pr in these 
tissues. X320. 
Fig. I.—Section of one-third of the rectum in a compressed condition, showing 
the “precipitate” pr in the lumen /, but none in the chitinous layer chi, nor in 
the rectal glands rgl, nor in the muscular m layer. X 50. 
Fig. J.—Section through the middle of the ventriculus, showing the distri¬ 
bution of the “ precipitate ” pr in the lumen /, between the peritrophic mem¬ 
branes pm, in the epithelial ep and muscular m layers of the ventriculus 
and in the Malpighian tubules mal. X 50. The walls of the ventriculus were 
drawn diagrammatically. 
