author's abstract of this paper issued 

 by the bibliogbaphic service, march 14 



A STUDY OF TESTIS AND OVARY GRAFTS ON THE 



HEN'S EGG AND THEIR EFFECTS ON THE 



EMBRYO 



TADACHIKA MINOURA 



Zoological Laboratory, University of Chicago 



ONE TEXT FIGURE AND TEN PLATES (tHIRTY-SIX FIGURES) 



CONTENTS 



Introduction 2 



The grafts 4 



1 . Material . 4 



2. Experimental method 4 



a. Operation 4 



b. Examination 6 



3. Growth of grafts 6 



a. External observations 6 



b . Histological study 8 



c. Comparison of growth of testis grafts and ovary grafts 11 



d. Age of the embryo most suitable for grafting 11 



Anatomical study of the embryos , 12 



1. Development of sex-glands and sex-ducts in normal embryos 12 



a. Sex differentiation 13 



b. Degeneration of the right ovary 13 



c. Wolffian ducts 14 



d. Miillerian ducts 16 



e. Range of size variation in normal testes 18 



2. Development of sex-glands and sex-ducts in grafted embryos 19 



a. General resume of experimental results 19 



b. Description of embryos affected by testis grafts 21 



c. Description of embryos affected by ovary grafts 26 



d. Summary of intersexual characters produced by gonad grafts . . 29 

 Discussion 32 



a. Action of sex hormones 32 



b. Specific function 32 



c. Effect of duration of the grafts 33 



d. Effect of age of birds furnishing the grafted gonads 34 



e. Effect of age of the embryo at the time of grafting 34 



/. Degree of reversibility 35 



g. Conclusion 38 



Summary , 39 



Literature cited 40 



1 



