VI FOREWORD 



By the time the second edition appeared in 1948, Submicroscopic 

 Morphology had become generally accepted as an important branch 

 of the biological sciences. The morphologists who did not trust 

 indirect methods, willingly accepted the results of electron microscopy, 

 although electron optics are even more complicated than those of 

 polarized light or X-rays. But the objectively visible image has always 

 been the foundation of Morphology, and therefore research in Sub- 

 microscopic Morphology is henceforth governed by the remarkable 

 invention of the electron microscope. 



As a consequence, this third edition is centred on the results of the 

 electron microscope; the old indirect methods, however, are treated 

 as equally valid means of research. The polarizing microscope and 

 even the X-ray camera are more accessible to the average biologist 

 who is interested in iine-structures than the expensive electron micro- 

 scope. There are several excellent monographs on electron micro- 

 scopy, but there is no other synopsis of the value and the results of the 

 indirect methods in Submicroscopic Morphology. In the first rush of 

 publishing electron micrographs, many micrographs were produced 

 which would have been discarded as mere pictures of artefacts if the 

 conclusions of indirect methods had been considered. Where there is 

 doubt as to the accuracy of an electron micrograph, the results 

 estabhshed by indirect methods ought to be taken into consideration. 

 Any discrepancies between the interpretation of the results of indirect 

 methods and those of the electron micrograph must be cleared up 

 before a submicroscopic structure may be regarded as definitely 

 established. 



This book is written, not for specialists, but for students who are 

 attracted to this interesting field of research. It is merely an outline 

 and does not attempt to give full details, which should be sought in 

 the original publications quoted. The extensive literature published on 

 this subject since 1948 has been taken into account as far as it was 

 possible in this condensed monograph. It shows the enormous 

 development of Submicroscopic Morphology during this short period. 



Institut Fiir Allgemeine Botanik 

 der Eidgenossischen Technischen 

 Hochschule, Zurich. 



November, 1952. A. Frey-Wyssling 



