148 PROFESSOR W. H. THOMPSON. 



whole temporal lobe, did not impair the animal's sense of 

 hearing. 



Meanwhile the question had been attacked in another way. 

 The experiments of Baginski,^ who followed the degenerations 

 resulting from destruction of the cochlea in rabbits, together 

 with the researches of Flechsig and Bechterew,- who employed 

 the now well known embryological method of the former 

 investigator, showed that the auditory nerve of one side is 

 brought into connection with the posterior tubercle of the 

 corpus quadrigeminum, and with the internal geniculate body 

 of the opposite side, by means of the contralateral fillet. 



Prior to this, V. Monalcow^' who extirpated definite regions of 

 the cortex of the brain in new-born animals, and afterwards 

 followed the tracts of arrested development which resulted from 

 these operations, had come to the conclusion that fibres from 

 the ventral part of the temporal lobe end, some in the corpus 

 geniculatum internum, others in the posterior tubercle of the 

 quadrigeminate body, and still others, pass directly down into 

 the fillet. 



The difficulties attendant upon the accurate bracing of conduct- 

 ing paths within the brain prevented these results from being 

 finally accepted as conclusive, and since their publication many 

 investigators have engaged in work more or less intimately 

 connected with this field. 



Held,^ who employed the newly introduced method of Marchi 

 for showing degenerated tracts, was enabled to fully confirm the 

 observations of Flechsig and Bechterew regarding the central 

 connections of the auditory nerve. Von Monakow, who likewise 

 carried out an investigation on this part of the subject, has also 

 arrived at results which, in the main, agree with those of 

 Flechsio-, Bechterew, and Held. He takes a different view, 



1 Baginsld, B., " Ueber d. Urspr. und centr. Verlauf d. Nerv. acust. d. 

 Kaniiichens," Virch. Archiv, 105, s. 28-46. 



- Flechsig, P. (with Bechterew), " Zur Lehre. v. centr. Verlauf d. Sinnes- 

 Nerv," Neurol. Centr., No. 23, s. 545-551. 



'■'' V. Jlonakow, " Ueber einige durch extirp. circumscr. Hirnriiid-Reg. 

 bedingt Entwickelungshenun. d. Kaninch-Gehirns," Arcidv f. Psych., xii. 1, 

 141 ; also xii., s. 535-549. 



'• Held, " Die cent. Bahnen des Nerv. acust. bei d. Katze,'' Archiv /■ Anat. 

 u. Physiol., Anat, Abt., 1891. 



