AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, FEBRUARY 27 
THE DEVELOPMENT OF THE SACCUS ENDOLYM- 
PHATICUS IN RANA TEMPORARIA LINNE 
BEATRICE WHITESIDE 
Zoological Laboratory, University of Zurich 
NINETEEN FIGURES 
INTRODUCTION 
The membranous labyrinth of vertebrates has often been made 
the object of close study. There is one structure, however, 
connected with the ear which has hitherto received very little 
attention, namely, the saccus endolymphaticus. It is true that 
the topography of this organ is well known in most animals, but 
we are as yet badly informed as to its development, histology, 
and function. 
Under these circumstances, I have, at Professor Hescheler’s 
suggestion, undertaken an investigation of the development of 
the saccus endolymphaticus in Rana temporaria Linné. The 
work was done in the Zoological Laboratory of the University of ° 
Zurich, Switzerland, under the guidance of Prof. K. Hescheler, 
and I wish to take this opportunity of thanking him for the assis- 
tance he has so kindly given me. I also wish to express my 
thanks to Prof. J. Strohl, Dr. Marie Daiber, and Dr. H. Steiner, 
of Zurich University, for their many helpful suggestions, and 
I am indebted to Mr. A. Bychowsky for the execution of figures 
LI to:.19. 
The present paper is divided into two principal parts: First, 
a description of the development of the saccus endolymphaticus 
in Rana temporaria Linné, and, second, an account of the topog- 
_ raphy of this structure in the different classes of vertebrates 
‘and the conclusions to be drawn from the same. 
In order to show the relation of the saccus endolymphaticus 
to the other parts of the labyrinth, I shall preface my report 
with a short summary of Gaupp’s (’04) description of the 
frog’s ear. 
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