Vol. XX. February, 1911. No. 3 



BIOLOGICAL BULLETIN 



THE METHOD OF CELL DIVISION IN THE 

 DEVELOPMENT OF THE FEMALE SEX 

 ORGANS OF MONIEZIA. 1 



A. RICHARDS. 



TABLE OF CONTENTS. 



Introduction 123 



Review of the Literature 126 



Material and Methods 130 



Fixatives 132 



Observations 134 



The Primary Anlage 135 



The Oogonial Period 141 



The Growth Period and the Behavior of the Nucleolus 142 



Synapsis 144 



Yolk Production 144 



The Ovarian Egg 145 



The Vitellarium 145 



The Female Genital Ducts 147 



Fertilization and Maturation 150 



Cleavage 152 



Summary of the Evidence 155 



Discussion 158 



Comparison with Tcenia .' 160 



Conclusions 161 



Literature References 162 



Explanation of Plates 164 



INTRODUCTION. 



Cestode histology has been the subject of several investigations 

 in recent years, some of the results of which are of far-reaching 

 importance. Throughout the development of Moniezia Child 

 has reported the regular occurrence of amitosis; he has described 

 it as present not only in the somatic tissues but also in the germ 

 cells. It was this latter phase of his results which occasioned 

 the present work. 



Zoological Laboratory, Princeton University, January 26, 1911. 



123 



