JUL 31 1902 



(From the Anatomisches Institut, Freiburg i. Br., and University College, Cardiff.) 



On the Perilymphatic Spaces of tho Amphibian Ear, 



By 



H. Spencer Harrison, 



Demonstrator and Assistant-Lecturer in Zoology, University College, Cardiff. 



(With Plates XI— XIII and 3 Figures in the Text.) 



Contents. 



I. Introduction. ^V- Discussion of Ptesults, with a theory 



TT mi Ti -1 1 ,• f^ , • ,, as to the origin of the Fenestra 

 il. ine Fenlymphatic System m the ,., ^. , °, 



, , vestibuli (ovalis). 



V. Summary and Conclusions. 



III. The Perilymphatic System in the yi. Bibliography. 



^T^^ra. VII Description of Plates. 



I. Introduction. 

 The perilymphatic system of the Amphibian ear has been des- 

 cribed, in greater or less detail, by Hasse [1, 2, 5], Eetzius [4], Kuhn [5], 

 Villy [6], and Gaupp [7]. The work of Eetzius is regarded as the stan- 

 dard book of reference for questions dealing with the Vertebrate ear, 

 and his description of the perilymphatic system is the one commonly 

 accepted. According to his accounts, the space between the walls of 

 the auditory capsule and the membranous labyrinth (the cavum peri- 

 lymphaticum), is occupied by a loose meshwork of connective tissue, 

 in the interstices of which is the perilymph, and through which the 

 nerves and bloodvessels run. The membranous labyrinth is, there- 

 fore, assumed to float more or less freely in the perilymph, being 



