AUTHOR 8 ABSTRACT OF THIS P.VPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, MARCH 28 



THE DEVELOPMENT OF THE EYE AND ITS ACCES- 

 SORY PARTS IN THE ENGLISH SPARROW 

 (PASSER DOMESTICUS) 



JAMES ROLLIN SLONAKER 



Stanford University, California 



TEN TEXT-FIGURES AND SEVENTEEN PLATES (FIGURES 1 TO 105) 



CONTENTS 



Introduction 263 



Eyeball in general 265 



The cornea, iris, and aqueous chamber 269 



The lens 277 



The vitreous body 286 



The chorioid and sclerotic coats : 288 



The pecten 292 



The retina 297 



The fovea 310 



The muscles of the eye 313 



The eyelids 315 



The lacrimal glands 318 



Literature cited 320 



INTRODUCTION 



The published descriptions of the development of the eye of 

 the bird have been largely confined to the domestic fowl, Gallus 

 domesticus, which has an incubation period of twenty-one days. 

 The incubation period of the English sparrow is about thirteen 

 days — approximately that of a large number of our wild species. 



The purpose of this paper is to describe the development of 

 the eye and its accessory parts of the sparrow and to correlate 

 the facts with the known conditions in the chick and other 

 animals. In this manner it is hoped to ascertain if there be 

 any difTerence in development of a domestic and a wild species. 

 Domestication has caused changes of habits, and it may likewise 



263 



