cxx Journal of Comparative Neurology. 



While the author does not go to the extent which Forel does in 

 claiming that the degeneration is similar in nature in the sensory and 

 motor roots, he thinks loss of function is chiefly responsible for the de- 

 generation of motor roots and that the alteration first appears in the cell 

 and afterwards affects the fibre. 



It was also found that pulling out the facial causes degeneration in 

 the corpus trapezoides. This is perhaps due to mechanical injury, as 

 simple section of the nerve does not produce the same result. Section 

 of the trigeminus by means of a neurotome after Magende's method, 

 though difficult, was carried out. Both the sesory (major) and motor 

 (minor) portions were found degenerate. In the ascending root the de- 

 generation could be followed into the cervical medulla. The median 

 portion of the portio major corresponds to the ventral part of the ascend- 

 ing root and the lateral part corresponds to the dorsal part of that root. 

 Only fe\y fibres seem to come from the sensory nidulus. 



The motor root (minor) was degenerate in all cases where the third 

 ramus was cut. The tract passes dorsad and somewhat cephalad. The 

 descending root (from the giant cells over the aqueduct) was always de- 

 generate. The author regards these as motor, because of their connection 

 with the portio minor. 



Injury of the pyramidal tracts caused descending degeneration as far 



as to the decussation, but nothing definite could be followed in the cord. 



■ The partial crossing of the oculomotor fibres, described by v. Gud- 



den, is substantiated. The paper is accompanied by three lithographic 



plates. 



The Roots of the Trigeminus. i 



These observations were made on the human fcetus and lower ani- 

 mals, chiefly by the method Weigert-Pal. • 



The ascending rooi Jiires appear at the level of the second cervical 

 nerves by an increase in the volume of the gelatinous substance and the 

 fibres on its mesal margins. The latter pass cephalad and then arch lat- 

 erad, passing through the substantia gelatinosa, and form the ascending 

 root on the lateral margin of the gelatinosa. This arching outward of 

 the fibres continues to the level of the sensory nidulus of the trigeminus. 



1. PoMiRTOWSKi; A. Ueber die Trigeminuswurzel liu Gehirue dcs Menschon, 

 nebst einigen vergleichend-anatoraischen Bemerkungen. Arbeiten aus deiii Inst. f. 

 Anat. u. Phys. des Centralncrvpiisysteras. Vienna. 



