102 
Journal of Agricultural Research 
. Vol. VII, No. 3 
canal. While the bees placed into the colored water struggle and cling 
to one another for several moments after being submerged, those placed 
into the colored nicotine solution struggle little and never cling to one 
another. They seem to be slightly paresized as soon as put into the 
solution, and perhaps for this reason alone they swallow little of the 
liquid. Paresis may also be used to explain why the colored liquid is not 
forced from the honey stomachs into the ventriculi. 
That the colored, liquids were never seen in any of the tracheae of 
the 60 bees submerged demonstrates that the valves guarding the 
spiracles closed water-tight at the instant of placing the bees into the 
liquids. That one-half of the bees submerged in the nicotine solution 
did not swallow any of it indicates that these valves can not be closed 
air-tight, because there seems to be no way of explaining why the bees 
were paresized other than by supposing that vapor from the nicotine 
solution passed the valves and entered the tracheae. Of course, the vapor 
might have entered the insects through the mouths and anal openings, 
but this view is highly improbable, and the liquid had not penetrated 
the integuments even at the thinnest places. . 
To determine whether the red liquid passed through the thin chitinous 
layer of the honey stomachs, several of these organs which were almost 
full of the red liquid were removed after both ends of a honey stomach 
had been securely ligatured with thread. Immediately after a honey 
stomach had been dipped into water to moisten its walls, it was gently 
rolled on white paper. No red liquid was seen issuing through its walls; 
nor was any observed on the paper. The same experiment was repeated 
by using the ventriculi. In this case red liquid was plainly seen to issue 
from the walls of each ventriculus, and it made the paper red. Thus, 
it seems that the red liquid usually seen surrounding the viscera of these 
bees when cut open had not passed through the walls of the honey stom¬ 
achs, but through those of the ventriculi and probably to a limited degree 
through the walls of the small intestines and those of the rectums, 
although it is shown on page 108 that a nicotine solution containing 
indigo-carmine does not pass through the walls of the small intestine 
and rectum. 
In all the preceding experiments liquids colored with stains have 
been used. It is probably true that many stains increase the permea¬ 
bility of their solvents and consequently may also increase the ability 
of the solvents to pass into small openings, such as the spiracles. For 
this reason coccids (Orthezia insignis) were submerged for 30 minutes 
in a pure nicotine solution (1 moo) which had not been colored with 
a stain. They were then fixed for 15 minutes in a mixture consisting of 
two parts of absolute alcohol and one part of phosphomolybdic acid. 
To insure the removal of all the phosphomolybdic acid not united with 
the nicotine and to insure better fixation, the insects were put into a 
mixture consisting of two parts of absolute alcohol and one part of 
