Berkley, Bitrinsic Pulmonary Nerves. in 



simple knobs, seemingly between the smooth muscular cells of 

 the middle coat of the vessel. Few ganglion cells are to be 

 found at the margin of the plexus, but local enlargements of the 

 fibres are common. 



The nerve distribution to the artery and bronchial tubes 

 are intimately connected, nerve fibres not only wander off from 

 the main bundles that follow the vessels, but from the vascular 

 plexus itself come off quite numerous rami that are distributed 

 to the smooth muscle, and to the epithelial lining of the air 

 tubes, perhaps after the formation of numerous anastomoses and 

 peculiar figures upon them. 



Nerve plexuses also accompany the pulmonary arteries, 

 but are not so well developed as those about the bronchial, still 

 traces of them are rather frequently met with in the form of 

 single fibres and portions of anastomosing networks following 

 the direction of the artery, and here and there an occasional 

 end-knob may be found bearing the same relation to the mus- 

 cular layer as it does in the bronchial arteries. Nerve fibres in 

 sparce numbers may also be found on the walls of the larger 

 veins, but upon the smaller as well as upon the walls of the 

 capillaries they are not to be seen. 



June 24, '93. 



DESCRIPTION OF PLATE XIV. 



Fig. I. — Intricate nerve termination from the muscular layer of a medium 

 sized bronchus. The dotted line indicates the internal margin of the muscular 

 zone. 



Fig. 2. — Two adjacent infoldings of the mucous membrane of a larger 

 bronchus, showing the relation of the nerve fibres to the epithelial cells. 



Fig. 3. — Complex termination of a nerve fibre from from the epithelial 

 lining of a bronchiole. The dotted line indicates the internal margin of the 

 epithelium. A, marks what is apparently a small ganglion cell interposed in the 

 path of the transmitting fibre. 



Fig. 4. — Nerve bundles and single fibres in the septa between the air 

 cells. From the mid-region of the lung. 



Fig. 5. — Drawing from a arterio-bronchial plexus showing the intimate re- 

 lation between the two. A, A, fibres arising from the plexus distributed to the 

 layers of the bronchus. The x indicates the margin of the peri-bronchial 

 spaces. 



All the drawings are from picric-acid-osmium-bichromate hardened speci- 

 mens, stained with silver nitrate. Zeiss, ocular 4, objective DD. 



