AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, DECEMBER 22 
SEX STUDIES 
XI. HERMAPHRODITE BIRDS! 
ALICE M. BORING AND RAYMOND PEARL 
NINE TEXT FIGURES AND NINE PLATES 
1. INTRODUCTION 
Studies IX and X of this series have dealt with the normal 
structure of the reproductive organs in the domestic chicken. 
That matter was undertaken as a preliminary to the study of 
certain hermaphrodite birds which have come into the posses- 
sion of the Maine Agricultural Experiment Station. It is only 
possible to interpret abnormal conditions in the light of and by 
comparison with the normal. The present study undertakes a 
description of the external sex characters and internal reproduc- 
tive structures or these abnormal birds. The general bearing of 
both normal and abnormal structures in the reproductive sys- 
tems of the chicken on theories of secondary sex characters will 
be discussed in still another paper, which has to be delayed for 
some time as one of the authors (R. P.) has been called by the 
government to turn his attention to war time problems. 
Il. MATERIAL AND METHODS 
The material for this study comprises a large number of birds 
belonging to the poultry plant of the Maine Agricultural experi- 
ment Station. The work has centered around eight hermaphro- 
dite birds. Five of these birds were bought from Herr Houwink, 
a well known writer on problems of heredity and evolution in 
poultry, in Meppel, Holland. They are Drentisch fowls, the 
common breed of North Holland. He states that “these fowls 
1 Papers from the Biological Laboratory of the Maine Agricultural Experiment 
Station No. 116. 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 25, NO. 1 
FEBRUARY, 1918 
