INTRODUCTION 



Subscribers are herewith receiving the eighth full issue, containing the new 

 data collected during 1959. 



Up till now the periodical has contained almost exclusively zoological data. 

 The progress of research has shown that, particularly in the field of develop- 

 mental biology, the distinction between zoology and botany is artificial. Many 

 problems attacked by botanists are closely related to those on which zoologists 

 are working. Therefore the periodical will henceforth embrace developmental 

 biology in general, particularly in so far as its experimental aspects are con- 

 cerned. For the time being the data on experimental developmental morphology 

 of plants are listed in a separate section of the "List of subjects" (see page 217). 

 The number of data collected this year is still limited, but we expect that it 

 will increase during the coming years. Suggestions for further improvement 

 will be gratefully considered. 



Contacts have this time been established with Eastern Germany, and the 

 contacts with India, Czechoslovakia, Hungary and Western Germany have 

 been extended. 



From 1950 till 1957 the subscription price has undergone no change, notwith- 

 standing the fact that the coverage and size of the periodical have increased 

 considerably (number of collaborators by about 50 %, number of institutes 

 by about 75 %, and number of pages by about 50 %). Moreover a number 

 of new chapters were opened during this period. In order to keep the periodical 

 "self-supporting", an increase of the subcription price has become unavoidable. 

 As already announced in the Supplement to the seventh issue, for the coming 

 years the price has been fixed at H.fl. 28.50 (i.e. $ 7.50) . 



P. D. NIEUWKOOP 



