106 O. LARSELL 
MATERIAL AND METHODS 
Rabbits weighing 3 to 4 pounds were used for the greater part 
of the present investigation. Various modifications of the 
methylene-blue technique were tried. The best results were 
obtained by using 0.05 per cent methylene-blue in Locke’s 
solution or in 0.9 per cent NaCl solution. Both Griibler’s and 
Harmer’s methylene-blue were employed with about equal 
satisfaction. 
The best staining of the nerve terminations in the bronchial 
tree resulted from injecting the warm stain into the pulmonary 
blood-vessels, through the right ventricle. On the other hand, 
the best preparations showing the innervation of the pulmonary 
vessels were obtained by filling the lungs through the trachea, 
by means of a funnel, with the warm stain. The lung was filled 
to about normal maximum distention, when the stain was intro- 
duced through the trachea, or was inflated with air to about the 
same degree of distention after the stain was injected into the 
pulmonary vessels, when that procedure was adopted. 
Following either method of introducing the stain, the lung 
was allowed to lie undisturbed in situ for ten minutes. In those 
cases in which the stain had been introduced by way of the 
trachea, the excess stain was then drained off. In the other 
cases in which it had been injected into the blood-vessels this 
was not necessary. The lungs were then alternately inflated 
with air and deflated, at the rate of twelve to fifteen times per 
minute. This was accomplished by means of a rubber-bulb 
hand blower which was connected to a cannula inserted into the 
trachea by means of a rubber tubing and a Y-glass connection. 
A short rubber tube with a pinch-cock was attached to one arm 
of the Y connection. The blower and the cannula were con- 
nected by tubes with the other two arms, respectively. Defla- 
tion of the lungs was accomplished by opening the pinch-cock 
and pressing gently with the hand on the outer walls of the 
thorax. The thoracic cavity had previously been opened to 
allow of observation of the process of staining. 
