1889 - 90 .] Dr Alexander Bruce on Third Cranial Nerve. 169 
This appears a more natural grouping, from the fact that the three 
elevators of the eye and eyelid, which habitually act together, are 
placed in juxtaposition, whereas, as has been pointed out by 
Manthner in his Nuclearldhmung, Hensen and Yolckers placed 
a depressor, the rectus inferior, between two elevators, thus separat- 
ing it also from its associated centre, that for superior oblique. 
Kahler and Pick found in one case in which the elevators were 
paralysed that the most external of the hinder (or lowermost) roots 
of the third nerve had degenerated, and in another case of paralysis 
alfecting the rectus interims that the postero-median rootlets were 
degenerated. Manthner (. Nuclearldhmung ) is inclined to accept the 
arrangement of nuclei just described. Yon Gudden ( Tgbltt . der 
Naturf. u. Aerzte , Salzburg, 1880, p. 100 ; and “ Mittheilungen der 
Morph, physiolog. Gesellschaft zu Miinchen,” Aertzl. Intellig. Blatt ., 
1883) found in the rabbit two nuclei on each side, a ventral and a 
dorsal. The ventral or anterior was connected with the nerve of 
the same side, the dorsal or posterior with that of the opposite side. 
Thus the right third nerve would arise from the right ventral and 
the left dorsal nucleus. He further divided the ventral into two 
parts, an anterior ( i.e ., nearer the cerebrum *?) and a posterior portion. 
Merkel (G-raefe Saemisch. Handbuch d. Ges. Angenheilkunde , i. p. 
135) and Yulpian and Philippeaux (Essai sur Vorigine deplusieurs 
paires de nerfs craniens) admit a decussation of some of the fibres of 
the third nerve, but Duval denies its existence. 
Edinger ( Westphal’s Archiv , 1885, p. 858) describes a median 
nucleus lying between the two principal nuclei, which sends fibres 
to each of the two nerves. Darkschewitsch ( Neurolog . Centralblatt , 
1886, Ho. 5) describes a small-celled nucleus at the upper extremity 
of the posterior longitudinal fasciculus, which he regards as probably 
forming part of the oculomotor nucleus. 
Westphal (Arch. f. psychiatrie, xviii. p. 847) found in a case of 
ophthalmoplegia externa that the main part of the oculomotor 
nucleus was degenerated, while two other groups of nuclei remained 
normal. One of these lay a little to the side of the raphe, and is 
named medial by Westphal. The other, or lateral, lies somewhat 
external to the posterior extremity of the medial nucleus. He 
apparently does not recognise a nucleus altogether in the median 
plane. (Westphal’s paper contains a very exhaustive account of the 
