NERVE TERMINATIONS IN LUNG OF RABBIT 123 
_ If these results can be applied to the mammalian lung, one 
might expect to find two physiological types here also. It 
appears possible that many of the fine nerve fibers which are 
present in the intrapulmonary nerve trunks are not related to 
the intrapulmonary ganglia, either as preganglionic or post- 
A. 
Fig. 11 Muscle bands from a bronchus, under higher magnification, illustrat- 
ing the manner in which the nerve fibers terminate. Rabbit Rl, series Al. 
Methylene blue, with aurantia counterstain. 25u. Camera lucida. X 560. 
ganglionic fibers, but represent fibers from some source outside 
the lung, which reach the lung by way of the vagus nerve and are 
distributed to the smooth muscle within this organ. This 
supposition may serve to account for the very rich innervation 
of the muscles of the bronchi, particularly. This innervation 
is much richer than the processes from the intrapulmonary 
ganglionic cells would appear to account for. 
