CHAPTER X 



MORPHOLOGICAL INVESTIGATIONS ON ADVENTITIOUS 

 FORMATIONS AND REGENERATION PHENOMENA 



The younger biologists who are familiar with BEIJERINCK'S micro- 

 biological work only, and perhaps know also something of his general 

 biological considerations set forth in his later years, will surely be 

 surprised when they study the investigations which occupied him in 

 the years before 1890. Apart from being a specialist in plant-galls, 

 BEIJERINCK in those years appears also to have been a full-fledged 

 plant morphologist. 



We have observed before that BEIJERINCK'S studies on galls taught 

 him early the value of experimentation in biology. This is probably the 

 explanation of the wide use he made of experiments in his mor- 

 phological investigations. A great part of BEIJERINCK'S botanical 

 work may be regarded as belonging to the field of "experimental 

 morphology". 



In Part I of this biography we have seen that circumstances led 

 BEIJERINCK, after the year 1885, to spend his time especially on other 

 problems, and we have observed that plant morphology receded into 

 the background in his studies after 1890. But his interest in it did not 

 disappear completely, and in later years short morphological studies 

 of especial attraction appeared unexpectedly. BEIJERINCK'S last 

 paper in fact, belonged to the field of plant morphology. During the 

 last years of his life the problem discussed therein, namely that of 

 phyllotaxis, occupied his mind more exclusively than any of the 

 numerous subjects with which his tireless labours of forty years' 

 duration brought him in contact. 



It is strikingly apparent in these morphological studies that BEIJE- 

 RINCK did not restrict himself to very minute observations and de- 

 scriptions of structures, or of changes in those structures after ex- 

 perimental interference, but that he drew conclusions from his ob- 

 servations on life-phenonema in general. Repeatedly, ontogenetical 

 and phylogenetical problems were brought forward in these morpho- 

 logical studies, and especially did he trace the fundamental properties 

 of the protoplasm of plant and animal. 



Apart from a short paper of the year 1881 "Over het hoefblad" l ) 

 (On Coltsfoot; Tussilago Farfara), which was based especially on a 



!) Tijdschrift voor Landbouwkunde, Groningen 1881, 56, biz. 138-148 (Vei 

 de Geschriften 1, 81-89). 



