AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, MARCH 20 
THE ORIGIN OF THE OTIC AND OPTIC PRIMORDIA 
IN MAN 
G. W. BARTELMEZ 
Department of Anatomy, The University of Chicago, and the Laboratory of 
Embryology, Carnegie Institution of Washington 
TEN FIGURES 
INTRODUCTION 
The early history of the nervous system in man and in the 
great majority of other mammals is but imperfectly known. 
In the whole order there is only a single detailed study of the 
origin of the cranial ganglia. The data on this phase of human 
development are for the most part included in descriptions of 
single specimens; they are few and incomplete and marred by 
faulty interpretations due to the lack of a human series and 
neglect of comparative material from other forms. 
We shall here confine our attention to the otic and optic pri- 
mordia, although the identification of them in the various em- 
bryos of the series is based in part upon our interpretation of the 
primary subdivisions of the nervous system. This evidence 
will be presented in a subsequent paper. 
MATERIAL 
The present observations are based upon the study of com- 
plete serial sections of twelve normal embryos ranging between 
stages of three and sixteen somites. In addition, the data from 
the published descriptions of four others have been available, 
so that the series is a reasonably complete one, even though some 
of the specimens leave much to be desired in the matter of histo- 
logical detail. We have models of eight of the embryos, and in 
the case of some of them several models were prepared. The 
specimens studied in this connection are as follows: 
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