326 On Certain Bacteria from the Air of New York City. 



Identification of Old Descriptions. 



In regard to insufficiently described species, two courses seem 

 open. We may discard the names of all such and redescribe each 

 as it occurs, or we may appW the name to any species which does 

 not contradict the author's original description and complete the 

 characters from that species. To assist in the recognition of 

 specific descriptions in the higher forms of life, there is usually 

 to be found the original example, or "type," which was before 

 the author and from which it can always be learned what form 

 was intended b}' the description, however imperfect; when the 

 type is lost, the description, if unrecognizable, is discarded. But 

 in the bacteria, the preservation of t3'pes is for the most part, out 

 of the question (since they must be alive), and the former course 

 becomes objectionable, not only in that such a large number' of 

 names would have to be discarded, but also that this number 

 would be variable in the opinion of different authors. Further, 

 as time went on, the discover}^ of new species might render the 

 description of an old one incomplete. According to the second 

 course, every name is to be preserved, the imperfect description 

 being completed by subsequent authors, provided they do not 

 identify as the old species a form which in au}^ way contrdicts 

 the original description, and all additions so made are to become 

 a part of the characters of the species. It would appear either 

 that all imperfect descriptions should in future be omitted from 

 our books, or some concerted attempt should be made to com- 

 plete them. If the latter course be thoroughly applied, and au- 

 thors can be induced to refrain from describing new species 

 unless no old name can be made to apply, and further, if a new 

 name seems necessaiy,to show good characters by which the new 

 form can be distinguished from its nearest allies, then we ought 

 in time to obtain a series of characterizations from which it 

 would be easy to determine a given species, and the science of 

 descriptive bacteriolog}' might be placed on a footing of pai'tial 

 equality with other branches of natural science. 



It is to be remarked that this branch of the subject has suffered 

 from its close connection with the study of medicine. Not only 

 have the non-pathogenic saprophytes received scant attention, but 

 the eager desire to isolate the active agent in the cause of diseases 

 has led to the naming of many bacteria from very insufficient char- 

 acters. It would seem that descriptive bacteriology belongs to the 



