CHAPTER XII 



MINOR MORPHOLOGICAL RESEARCHES 



In 1885 there appears a short but especially attractive communica- 

 tion on the subject of "Gynodioecie bei Daucus Carota L." l ], wherein 

 BEIJERINCK shows that the occurrence of gynodioecism has been 

 overlooked up to the present in this common wild flower. Two groups 

 of this plant may be distinguished, which may occur side by side in 

 nature. One of the groups possesses snow-white umbels with a central- 

 ly-placed small umbel or central flower of dark brown-red colour. The 

 second group is characterized by greenish-red inflorescences which 

 appear during the blossoming time to be already past their bloom, 

 while in reality they are not, since they continue to have a corolla after 

 fertilization, and the leaves of the corolla enlarge in size even there- 

 after. The flowers of the first group are normally androgynous ; those 

 of the second group possess also completely developed ovules and 

 anthers, with apparently normally-developed pollen, but the anthers 

 of the last mentioned flowers always remain closed. The plants of this 

 latter group are therefore "physiologically female". 



It is needless to say that BEIJERINCK elucidated his considerations 

 with neat drawings. Also, he did not restrict himself to a simple 

 description of this, in itself, rather interesting case. He added a general 

 consideration on the value of gynodioecism in the vegetable kingdom. 

 It is of note that he could not consider it of any use. He even stated : 

 "Ja, ich mochte die Eigenschaft der Gynodiocie der Mohre eben als 

 eine schadliche betrachten, allein nicht so schadlich, dass dadurch die 

 Existenz dieser weit verbreiteten und kraftigen Species bedroht 

 ware." Here again one is given the impression of a very modern opi- 

 nion on a problem which biologists have thought about for many 

 years, but on which different opinions have often been given. 



BEIJERINCK was further greatly interested in the remarkable forms 

 of some Coniferae classified as "Retinisporae". About 1852 C. KOCH 

 reported that he had obtained Thuya ericoides (also called Retinispora 

 ericoides), a garden plant imported from Japan as a separate species, 

 from a cutting of Thuya occidentalis. However, more attention was 

 drawn to such cases by the publications of L. BEISSNER in 1887 and 

 1889, wherein the latter established that in these cases "youth 

 forms", which deviate from the main forms, maintain themselves by 

 vegetative growth. Besides these main and youth forms, BEISSNER 



i) Nederlandsch Kruidkunclig Archief, 2e serie, 4e deel, 3e stuk, 345-354, 1885 (TVr- 

 zamelde Geschriften 1, 409-414). 



