VAN NIEL: SYSTEMATICS OF THE BACTERIA AND BLUEGREEN ALGAE 101 



On devrait se contenter de ce que les bacteries se laissent tout de meme systematiser, 

 sous forme de groupes representes par des Biotypes, qui sont, eux, bion differenciables. 



At first sight this approach may appear simply to avoid the species problem 

 by substituting for it the new one of what shall be considered the criteria for a 

 biotype. Yet this mere substitution may exert a healthy influence because the 

 name is still untinged by connotations such as those that have come to be asso- 

 ciated with the term "species." Also in connection with the problems to be dis- 

 cussed in the next section, acceptance of Winogradsky's proposal would go far 

 in removing obstacles that must otherwise be faced. 



The validity of these statements is well illustrated by the following example. 

 It can be reasonably expected that some of the "biotypes" established in the course 

 of time would correspond more or less closely with now accepted "true species" 

 of bacteria. The use of the latter term has, however, been restricted and is gen- 

 erally applicable only to the first described species of a genus, a situation that 

 results from the virtually complete acceptance by bacterial systematists of the 

 rules of nomenclature adopted by the botanists. Now, this inevitably entails the 

 consequence that a number of "type species" represent bacteria that have not 

 been studied in sufficient detail to make them acceptable as biotypes in the sense 

 in which I have interpreted this expression in the preceding pages, and which 

 would definitely include the availability of specific elective culture procedures 

 for the organism in question. Adherence to the present code of bacterial nomen- 

 clature would make it difficult to change a large number of "type species"; but 

 when "biotype" is used instead, no one is hampered by "rules and regulations" 

 that have not yet been formulated. 



Winogradsky's suggestions therefore appear to me worthy of careful consid- 

 eration and strong support; in a sense they represent a logical development of 

 my own ideas, expressed some years ago as follows (van Niel, 1946, pp. 297-298) : 



Discontinuation of the terms species and genus for bacteria, along with the introduc- 

 tion of multiple keys, would eliminate some of the difficulties now encountered, because 

 it would insure a far greater autonomy to specialists in dealing with their own groups 

 and problems, unencumbered by the exigencies of different groups. There would be no 

 need for the sort of consistency required as the foundation of a single system of clas- 

 sification. Whether the further elaboration of a rational nomenclature along the lines 

 laid down by Orla-Jensen, and further expanded by Kluyver and van Niel, would prove 

 adequate, or whether it might even be preferable to drop the use of Latin names with 

 their taxonomic implications, is a matter for future developments. And, while I am 

 fully in agreement with the opinion that stability in nomenclature is of great importance, 

 I must once more insist that, in the long run, it may turn out to be easier to gain adher- 

 ence to a more rational, modernized system than to the current one. 



The Genera, Families, and Orders of the Bacteria and Bluegreen Algae 



In the development of our system of classification the discovery and naming of spe- 

 cies with a generic and specific name came first. Grouping into Genera was followed 

 by grouping of Genera into Tribes and Tribes into Families and Families into Orders. 

 In developing the key in the reverse order, the authors of the keys in the Manual were 

 forced to use initially for identification characters which by their very nature are 

 largely indeterminable. — V. B. D. Skerman, 1949, pp. 177-178. 



What made Winogradslvy (1952) grant that the systematics of plants and 

 animals on the basis of the Linnean system is defensible, while contending that 



