ArXnOR's ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIELIOQR.VPHIC SERVICE. DECEMBER 15 



EMBRYOLOGY OF COCCIDS, WITH ESPECIAL REFER- 

 ENCE TO THE FORMATION OF THE OVARY, ORIGIN 

 AND DIFFERENTIATION OF THE GERM CELLS, 

 GERM LAYERS, RUDIMENTS OF THE MIDGUT, AND 

 THE INTRACELLULAR SYMBIOTIC ORGANISMS^ 



GEORGO ORIHAY SHINJI 



TWENTY PLATES (ONE HUNDRED THIRTY-THREE FIGURES) 



CONTENTS 



, . 73 



1 Introduction ^^ 



Historical „„ 



Material and methods 



2 The origin and differentiation of the ovarian elements »^ 



3 The egg gy 



4 Cleavage ; ' V ' V " j on 



5 Establishment of the external form of the body ^ 



6 The formation of the germ layers and embryonic envelopes ^^^ 



7 The formation of the nervous system ^^^ 



8 Intracellular sjonbiosis ^^2 



9 The origin of the germ cells ^^^ 



10 The formation of the digestive tract 121 



11 Summary -^^j 



Bibliography 



1. INTRODUCTION 



Historical 



On account of their economic importance, scale insects have 

 been the object of extensive observations by several inves- 

 tigators. The Uterature pertaining to these insects is, however, 

 lunited in its scope, being mostly concerned with the external 

 morphology, general accounts of the life history, habits, and 

 methods of control. The accounts of the formation of the egg 

 and subsequent history of the development of coccids are mostly 



lA thesis submitted to the faculty of the Graduate School of the University 

 of Missouri for the degree of Doctor of Philosophy. 



73 



