108 O. LARSELL 
The sensory nerve terminations in the epithelium of the primary 
bronchi consist of elaborate ramifications of relatively large mye- 
linated fibers (fig. 1). These fibers are given off from the nerve 
trunks which course along the bronchi, forming a loose longitudi- 
Fig. 1 Sensory nerve terminations in epithelium of primary bronchus within 
the lung. Rabbit Rl. Methylene-blue stain. Camera lucida. X 300. 
Fig. 2 Sensory nerve termination at the point of division of one of the larger 
bronchi: Rabbit Rl. Methylene-blue stain. Camera lucida. 50u. X 280. 
ABBREVIATIONS FOR ALL FIGURES 
art.pul., pulmonary artery mu.bd., muscle band 
br., bronchus mu.c., smooth muscle cell 
brl., bronchiolus n.fi., nerve fiber 
du.alv., ductulus alveolaris n.ter., nerve termination 
epith., epithelium n.tr., nerve trunk 
l.nod., lymph nodule po.fi., postganglionic fiber 
lu., lumen pr.fi., preganglionic fiber 
l.v., lymphatic vessel t.fi., terminal fiber to muscle cell 
nal meshwork on the walls of the air tubes, and pass singly or in 
small bundles of two or three fibers to the base of the bronchial 
epithelium. When they occur in strands of more than one 
fiber, these strands break up near the base of the epithelium 
into single fibers which supply separate areas. 
