108 



In the beginning of this paragraph mention has already been made 

 of the fact that his laboratory note-book reveals that he started his 

 investigation on May 25th, 1887. From this date onwards one finds 

 in the note-book a continuous report of observations regarding the 

 bacteroids of various leguminous plants, and also regarding cultural 

 experiments with bacteria obtained out of root nodules. On November 

 26th, 1887, Beijerinck reported the successful outcome of his in- 

 vestigations in the meeting of the "Koninkhjke Akademie van Weten- 

 schappen" at Amsterdam. Here for the first time a description of the 

 main properties of the root nodule bacteria was given, and the name 

 of Bacterium radicicola proposed ' ) . 



From his laboratory note-books one sees that Beijerinck took up 

 other objects of study soon afterwards. This may explain that almost 

 a year passed before a more detailed publication of the results of 

 Beijerinck's investigations on the root nodule bacteria appeared in 

 the "Botanische Zeitung" 2). It is noteworthy that in this paper no 

 mention is made of Hellriegel's work, although in a footnote to 

 the introduction the most important literature is given. Apparently, 

 Beijerinck confined himself here strictly to the bacteriological as- 

 pect of the problem, and at that time did not seem it necessary to 

 refer to Hellriegel's primarily agricultural investigations. 



It is superfluous to dweil here upon the importance of Beijerinck's 

 observations, the paper having become a classic of botanical litera- 

 ture. The circumstantial description of the bacteroids present in the 

 nodules of different Papilionaceae has remained unsurpassed. More- 

 over the paper contains detailed indications for the culturing of the 

 bacterium, the name of which is altered into Bacillus radicicola ^). 

 Beijerinck further proves that Bac. radicicola is unable to bring 

 about nitrification, and he also reports negative results of experi- 

 ments intended to demonstrate possible nitrogen f ixation by pure cul- 

 tures of the organism. 



Nearly two years later Beijerinck returned to this question in a 

 paper which also brings the first direct experimental proof for the 

 nodule forming power of Bac. radicicola when brought into contact 

 with aseptically-cultivated Vicia F aha seedlings "). Here again the 

 nitrogen-fixing power of the pure cultures of the bacterium is denied. 

 However, attention is drawn to the ability of the organism to form a 



1) A detailed abstract of Beijerinck's communication was published shortly after- 

 wards in: Versl. en Meded. Kon. Akad. v. Wetensch., Afd. Natuurk., Amsterdam 

 3de Reeks, 4,300, 1888. 



2) Botanische Zeitung 46, 725-735, 741-750, 757-771, 781-790, 797-804, 1888. 

 First part published November 16th, 1888. 



3) Beijerinck writes here the specific name: Radicicola (with capital R!). That 

 the change in generic name was not due to an altered insight into the systematic 

 position of the organism is clear from the following citation out of Beijerinck's 1891 

 paper on Bac. radicicola: "Which bacteriologist will not admit that what we call 

 Bacillus nowadays corresponds more or less to the genus "Chaos" of Linnaeus and 

 comprises essentially different groups?" 



") Botanische Zeitung 48, 837, 1890. 



