2 Journal of Comparative Neurology. 



Obersteiner (2) describes a preparation of the pia-mater, 

 taken from the convexity of the human brain, stained in gold 

 chloride, which has been in his collection for many years, and 

 which contained a small vessel (figured by him), on which a 

 number of relatively large nerve-fibrils were found. He states 

 that in this preparation, only the coarser nerve-branches seemed 

 stained, the finer branches, with their terminations remaining 

 unstained. " Es ist also" (he adds) "damit der directe anatom- 

 ische Beweis geliefert, dass die feineren intracraniellen Gefasse, 

 wenigstens innerhalb der Pia mater, ihre eigenen Nerven 

 besitzen. Daraus darf doch ohneweiters der Schluss gezogen 

 werden, dass diesen Gefassen auch die Fahigkeit zukommt, 

 sich activ, selbststandig zu contrahiren, respective zu dilatiren." 



These contradictory statements, taken in connection with 

 the fact that physiologists very generally deny the existence of 

 vaso-motor fibers in the intracranial vessels — if one may be al- 

 lowed to judge from their writings — led me to re-investigate the 

 question under consideration. Sometime after the completion 

 of my own observations, I was gratified to see a short abstract, 

 in which Gulland (3) states that on renewed investigation he had 

 been able to find nerves on the intracranial vessels. He there 

 states that : "In material from human brains and those of dogs 

 prepared by the Cox's method, given him by Dr. W. Ford 

 Robertson, he found nerves on a number of the vessels, and 

 saw that they presented the usual appearance of perivascular 

 nerve plexuses." At the Edinborough meeting of the British 

 Medical Association, microscopical specimens were shown in 

 proof of this fact. This abstract further states, that Dr. H, Mor- 

 rison, of London, had also been able to demonstrate these 

 nerves by Sihler's haematoxylin method. In consideration of 

 the fact that my own work was practically completed before I 

 became cognizant of the observations just given, and further, 

 since the methods adopted by me seem to differ in every respect 

 from those followed by the English observers, I see no incon- 

 sistency in presenting my own results at this time. The an- 

 swer to the question of the existence or non-existence of vaso- 

 motor nerves on the intracranial vessels is so necessary to a 



