Literary Notices. vii 



That some of the root fibers of the oculomotorius have a crossed 

 origin has long been known. In the rabbit he confirms the findings of 

 Edinger, Perha, Bach, and others that the dorsal and caudal part of the 

 common oculomotor nucleus gives rise to crossed fibers. The oculo- 

 motor nucleus of the rabbit is not obviously segmented in accordance 

 with the muscles supplied from it, yet experimentally it has been possi- 

 ble to analyze it and the details of its composition are given. The 

 nerves for the m. rectus superior (and perhaps for the superior levator 

 palpebrarum) are mainly of crossed origin, while a very few fibers for the 

 mm. obliquus inferior and rectus internus are also crossed. The tract 

 of Duval and Laborde between the VI nucleus and the third nerve of 

 the opposite side could not be demonstrated experimentally in the rab- 

 bit; that is, no cells of the sixth nucleus degenerated after section of 

 the branches of the third nerve, while, on the other hand, the section 

 of the sixth nerve was followed by chromatolysis in all of the cells of 

 the sixth nucleus. 



Section of the patheticus shows that its fibers almost all have a 

 crossed origin but that a very few cells of the nucleus of the same side 

 are also affected. Whether these fibers cross at their origins from the 

 nucleus and again in the valve of Vieussens was not determined. 



The abducens is formed exclusively in the rabbit of uncrossed 

 fibers. In 1893 Van Gehuchten described for the bird in addition to 

 the classical nucleus of the abducens a smaller more ventral nucleus. 

 This has been repeatedly demonstrated since in the mammals, but a 

 controversy has arisen as to whether it belongs to the VI or the VII 

 nerve. Section of the VII nerve in the rabbit was followed by no 

 change in this nucleus, while section of the VI nerve resulted in chro- 

 matolysis of these cells. 



II. The second contribution is devoted to the facial nerve. The 

 nucleus of origin in the rabbit runs between the superior olive and the 

 n. ambiguus and contains four quite distinct cell clusters, internal, ex- 

 ternal, middle and dorsal, all characterized by cells of the same type, 

 the motor type of Nissl. Section of the seventh nerve immediately 

 after its exit from the brain and subsequent study of the brain by Nissl's 

 method show that all^of the facial fibers arise from the nucleus as 

 above defined, and that all of the cells of this nucleus degenerate and 

 no others. No fibers arise from the opposite side. 



The peripheral relations of the several portions of the VII nu- 

 cleus of the rabbit were determined experimentally. Section of the 

 nerve immediately after its exit from the stylo-mastoid foramen caused 

 degeneration of all cells of the nucleus save the most internal ones of 



