Critical Digest. Ixvii 



regard occasional accidents such as : ' cases have been recorded in 

 which, after snch. lesion (division of the chorda tympani), the applica- 

 tion of stimuli to the disfal portion of the chorda tympani has caused 

 sensations of taste in the region in which it was lost or impaired.' — 

 Mills seems too ready to follow anatomical evidence in disputing the 

 correctness of observations speaking for a participation of the fifth 

 nerve in the taste perception; he does not even mention it among the 

 * accessory nerves.' In order to get rid of the cases of abolition of 

 taste after lesions of the fifth, he suggests the possibihty of simultaneous 

 involvement of the central ' gustatory tracts passing in the pons from 

 the oblongata to the cortex or in some cases even of the glosso- 

 pharyngeal or pars intermedia of Wrisberg at or near the stem'. And 

 ' in Horsley's operation by raising the temporal lobe it is possible to 

 injure the cortical tract and centers for taste.' These ' possibilities ' 

 are practically impossibilities. The circumscribed defects of sensi- 

 bility of taste on the tongue cannot reasonably be attributed to 

 'central' lesions; the motor apparatus suffers first and hemiparesis 

 and hemianaesthesia would most likely occur in such a lesion of 

 the pons before a limited hemiageusia ; and a search in real speci- 

 mens for the nervus Wrisbergii would have dispelled the idea that its 

 fibers would very probably be injured without involvement of the 

 seventh and eighth. Finally Horsley's operation would not under 

 the worst conditions lead even to a complete ' central ' deafness of the 

 opposite ear and certainly not to limited hemiageusia, not even to a 

 perfect hemiageusia, for which a complete decussation of the unknown 

 tract and clinical evidence would be a condition. 



The anatomy of the 8th nerve is very clearly described on ground 

 of the data of Ramon y Cajal, Held and also KoUiker. A good origi- 

 nal diagram gives an idea of the constitution of the eighth nerve (leav- 

 ing undecided to which portion the neurones supplying the saccule go). 

 By speaking of the " accessory nerves of hearing," Mills offers the 

 physician material for a very fruitful conception of the auditory mech- 

 anisms as a sensory-motor apparatus of great complication. There are 

 many reasons why the anatomist might consider Rauber's diagrams 

 overdrawn and partly decidedly inaccurate. Fig. 350 contains fibers 

 from the spiral ganglion reaching the posterior and the anterior opposite 

 quadrigeminum. Fig. 351 gives us a root fiber reaching the cortex, 

 the only other constituent of the cortical tract coming from the ' nu- 

 cleus of the lateral lemniscus,' while the best ascertained source, the 

 internal geniculate body is omitted. In this instance the text is cor- 

 recter than the diagrams borrowed. The portion on the vestibular 



