atjthob's abstract op this paper issued 

 by the bibliographic service, october 17 



THE DEVELOPMENT OF PARACOPIDOSOMOPSISi 



J. T. PATTERSON 



Universihj of Texas, De-partmont of Zoology 



TWO TEXT FIGURES AND TWELVE PLATES (NINETY FIGURES) 



CONTENTS 



1 . Introduction 1 



2. Structure, maturation, and fertilization of the egg 6 



a. The freshly laid egg 6 



h. Maturation 9 



c. Fertilization 13 



3. The cleavage stages 14 



a. The first division 14 



h. The second division 15 



c. The third division 18 



d. The fourth division 18 



e. The fifth division 19 



/. The morula stage 20 



4. Formation of the polygerm 24 



5. Historj^ of the polygerm 27 



a. Multiplication of the primary masses 27 



h. Relation of parasitic egg to host tissues 29 



c. Dissociation of the polj^germ 31 



d. Origin and history of the sexual embryos 33 



e. Origin and history of the asexual embryos 36 



6. Summary 39 



7. Bibliography 42 



8. Description of plates 45 



1. INTRODUCTION 



The object of the present paper is to give a rather complete 

 account of the development of a polyembryonic insect. We 

 owe a great deal to Marchal and Silvestri for their pioneer studies 

 in this field. They have given us a good outhne of the general 

 com'se of events in the development of some three or four species. 

 Nevertheless, there are many important points in the embry- 



^ Contribution no. 145. 



