il.Hfyi-^i ]oyi) 



EAELY STAGES OF DEVELOPMENT OF THE EABBIT. 113 



A Re-investigation into the Early Stages of the 

 Development of the Rabbit. 



By 



Richard Asslieton, M.A. 



With Plates 13—17. 



INTRODUCTION. 



It is now nearly fifteen years since Ed. van Beneden^ 

 published his account of the development of the early stages of 

 the rabbit ; and although I do not see that one can as yet 

 describe every detail of even the earliest embryology of the 

 rabbit strictly epigenetically, still it seems probable that van 

 Beneden took far too little heed of the extrinsic causes which 

 may direct the course of development. 



The effect upon the development of the presence or absence 

 of such structures as the albuminous layer or zona radiata has 

 been almost entirely ignored, apparently because they are 

 matter outside the ovum. So, again, the size and structure of 

 the uterus have hardly received their proper share of attention. 



The present paper and my other '' On the Causes which lead 

 to the Attachment of the Mammalian Embryo to the Walls of 

 the Uterus," tend, I hope, to show how many of the details of 

 the earliest stages may be ascribed to the direct maternal 

 influences. That is to say, the inherited force is an energy 



1 'La maturation de I'oeuf,' &c., Bruxelles, 1875; "La formation des 

 Feuillets chez le lapin," 'Arch, de Biologie,' vol. i, 1880. 



VOL. 37, PART 2. — NEW SER. H 



