INTRODUCTION 



In this supplement to the ninth full issue the chapter "Supply and demand 

 service for laboratory animals" has been omitted. On the one hand the in the 

 G.E.I.S. published data had become more and more fragmentary and on the 

 other hand other organizations, as e.g. "The International Committee on 

 Laboratory Animals" are taking over our task. A continuation of this service 

 would therefore lead to an overlapping of activities. 



This supplement therefore contains only the chapters: 



1 ) Changes of address p. 5 



2) Communications from the Hubrecht Laboratory and the "Inter- 

 national Institute of Embryology" p. 9 



3) Announcements of recently published books on development and 

 related subjects p. 11 



P. D. NIEUWKOOP 



