HuBER, hinervation of the Intfacranial Vessels. 25 



DESCRIPTION OF FIGURES. 



PLATE I. 



Fig. I. Circle of Willis and basilar artery of cat. Showing in a semi- 

 diagrammatic way the distribution of the sensory nerve fibers. Only afew of the 

 stained fibers sketched to give their course and distribution, i. anterior cere- 

 bral ; 2. middle cerebral; 3. posterior communicating; 4. posterior cerebral; 5. 

 basilar. For letters see text. 



Fig. 2. Portion of posterior cerebral artery of left side of cat showing 

 the termination of a sensory nerve fiber. Nerve with ending in the adventitia 

 of vessel. Methylen blue preparation fixed in ammonium picrate and mounted 

 in ammonium picrate glycerine. Magnification 900 diameters. Reduced to 

 one-fourth. 



Fig. J. One of the larger branches of middle cerebral of a cat. Methylen 

 blue stain. Shows perivascular vaso-motor plexus. Magnification 450 diame- 

 ters. Reduced to one-half. 



Fig. ^. Small pial vessel from dog. Vessel has two layers of involuntary 

 muscle cells. Shows perivascular vaso-motor plexus. Magnification 900 di- 

 ameters. Reduced to one-half. 



Fig. 5. Middle meningeal of cat. Methylen blue stain. Two bundles of 

 medullated nerve-fibers — sensory fibers — accompanying it ; m. vaso-motor 

 plexus in vessel. Magnification 150 diameters. Vaso-motor plexus sketched io 

 from higher power. Reduced to one- half. 



Fig. 6. From surface preparation of dura of cat. Methylen blue prepar- 

 ation. M. bundles of sensory, medullated fibers. Varicose fibers in sketch 

 terminal branches of sensory dural nerves. Magnification 450 diameters. Re- 

 duced to one-half. 



