MORPHOLOGY OF EYE MUSCLE NERVES 103 



somatic musculature may be considered serially homologous with 

 spinal somatic motor nerves. 



d. Conclusions regarding the morphology of the oculomotor. It 

 is scarcely necessary to say that the conclusion that the oculo- 

 motor is serially homologous with spinal somatic motor nerves 

 has not been reached by all morphologists. It is, however, the 

 opinion of the majority, including Van Wijhe ('82), Beard ('85), 

 Hoffmann ('86-'00), His ('88), Martin ('90), Dohrn ('90, '91), 

 Zimmermann ('91), Kolliker ('96), Neal ('96, '98), Koltzoff ('01), 

 Carpenter ('06), Filatoff ('07), Belogolowy ('08) and also, on the 

 basis of anatomical evidence. Muck ('15), Bell ('30), Stannius 

 ('49), Bonsdorff ('52), Budge ('55), Huxley ('74, '75), Schneider 

 ('79), Gaskell ('86, '89), Strong ('90), Fiirbringer ('97), Wieders- 

 heim ('98), Gaupp ('99). 



On the other hand, it has been regarded as a splanchnic motor 

 nerve homologous with the trigeminal by Balfour ('78), Marshall 

 ('81, '82), Dohrn ('85, '87), Houssay ('90), Hatschek ('92), 

 Sewertzoff ('98), and as a somatic sensory or mixed nervfe with 

 coenogenetic atrophy of the sensory element by Marshall ('82), 

 Rabl ('89), Martin ('90), Miss Piatt ('91), Mitrophanow ('92, 

 '93), Sedgwick ('94), Sewertzoff? ('99), Gast ('09), and on ana- 

 tomical grounds by Schwalbe ('79, '81) and Gaskell ('89.) 



The most recent argument in favor of the latter opinion is 

 that given by Gast. He admits that in its first anlage, the 

 oculomotor develops in the same way as the anlage of a somatic 

 motor nerve. On page 420 he states that naked neuroblast 

 processes grow from the neural tube, unite to form a naked fiber 

 bundle, grow to a segmental ganglion, and receive their sheath 

 cells from it. Medullary neuroblasts also migrate into the nerve 

 anlage. Sheath and sympathetic cells ^^'ander from the meso- 

 cephalic ganglion into the nerve anlage but retain connection 

 with their source by a ramus communicans, a phenomenon quite 

 in line with that of typical somatic motor nerves. 



On the other hand, he says, there are indications that lateral 

 horn elements are combined with these ventral root elements. 

 In the first place, the close relations with the mesocephalic gan- 

 glion through which the oculomotor fibers grow in some instances 



