VAN NIEL: SYSTEMATICS OF THE BACTERIA AND BLUEGREEN ALGAE 103 



fusing situation was made by a Committee of the Society of American Bacteri- 

 ologists whose members published reports and recommendations (Winslow et al., 

 1917, 1920) for the development of a more uniform system of classification of 

 the bacteria, largely based on Buchanan's proposals (1916-1918). This became 

 the nucleus from which originated in due course Bergey's Manual of Determina- 

 tive Bacteriology (1923-1948), prepared by an ever-increasing number of spe- 

 cialists with expert knowledge of various groups of bacteria (Breed et al., 1948). 

 The classification followed in this handbook has been more and more generally 

 adopted and is today the most widely used. 



But in spite of the growing recognition afforded the painstaking efforts rep- 

 resented by this collaborative enterprise, the end result has never been wholly 

 satisfactory, and each successive edition has come in for a certain amount of 

 criticism. Objections have been raised to the inclusion of a vast array of poorly 

 characterized species, for example by Winogradsky (1952) and Skerman, the 

 latter presenting a well-reasoned argument (Skerman, 1949, p. 175) : 



Many of the descriptions of bacteria in Bergey's Manual of Determinative Bac- 

 teriology are decidedly poor when viewed from present-day standards. Some will be 

 difficult to improve since a number of the original cultures have probably been lost. 

 The original descriptions which still remain on record present us with an awkward 

 problem in establishing priorities. Some of these descriptions are so inadequate that 

 one description could be equally well applied to many new isolates. The original authors 

 cannot be blamed for the inadequacy of these descriptions which no doubt conformed 

 to the standard of the day and it would be a breach of ethics to refuse recognition of 

 these descriptions. Nevertheless present-day workers cannot regain the original cultures 

 in some instances to subject them to further examination and would-be key formers are 

 handicapped by the lack of this information. Thus one cause of the chaotic state of 

 bacterial nomenclature is the lack of "type" specimens regarded as essential by syste- 

 matic botanists. There is only one remedy for this, namely the redescription of all 

 available cultures according to a certain code which should be applied to all bacteria 

 alike. On the basis of these descriptions the organisms should be renamed, for the 

 most part with the names they now possess. Priorities should be based on these names 

 and all descriptions and names for which there are no procurable cultures should, by 

 common consent, be discarded. 



Besides, the characterization of many of the genera has been found wanting, and 

 again I quote from Skerman (1949, p. 176) : 



There is also need for more precise definitions for genera. In the hands of the 

 authors of most of our textbooks the term "definition" has entirely lost its meaning. 

 Many of the definitions contain very little which is definite. They approach more to- 

 wards condensed, and often confusing, descriptions which attempt to embrace all the 

 possibilities which one may encounter among the species in the genus rather than a 

 precise statement of the characters which can be uniformly found among all or the 

 majority of species within that genus to be distinguished from other genera. 



And finally the taxa of higher order suffer from the same deficiency, here even 

 more aggravated because, as Skerman remarks (ibid., p. 177) : 



A close study of the number of determinable characters which could represent all 

 species within a genus would reveal this number to be very small. The number of 

 characters which are common to all genera within a tribe must inevitably be smaller, 

 and would continue to diminish as groupings become broader. 



These remarks should suffice to indicate that the satisfactory demarcation of 

 systematic units above the rank of species is beset with even greater difficulties 



