INTRODUCTION 



In the interest of the subscribers we should like to make the following remarks 

 concerning the contents of the ninth full issue. 



No essential alterations have been made in the general set-up of the 

 periodical. However, the organization of the "List of Subjects" (now called 

 "Subject Index", see page 194) has undergone a number of changes, particu- 

 larly as regards the key to organ systems, and the subdivisions of the main 

 rubrics. These changes are meant to render the system more logical, more 

 up-to-date and easier to use. 



A new general rubric has been added, entitled "Somatic Embryogenesis" 

 (see page 249). This name was chosen to encompass all developmental pro- 

 cesses associated with asexual propagation, which hitherto used to be classified 

 under one of the other general rubrics, but which in fact do not belong to 

 embryology proper. 



Some new contacts have been established with Argentine, continental China 

 and Greece, and the contacts with the U.S.S.R. and Eastern Germany have 

 been extended. 



Information concerning the Hubrecht Laboratory and the "International 

 Institute of Embryology" may be found on page 262 and on page 265 

 respectively. 



P. D. NIEUWKOOP 



NOTICE: As a result of a recent revaluation of the Dutch guilder, the equiv- 

 alent of the subscription price of H.fl. 28.50 is no longer $ 7.50, but now 

 amounts to slightly less than $ 8.00. 



