470 MUSGRAVE, CLEGG, AND POLK. 



DETERMINATION OF GENUS. 



It is difficult to determine upon the correct name of the diseases, 

 because of the botanical confusion regarding the position and designa- 

 tion of the group of organisms concerned, and of the lack of clearness of 

 definition specifying definite limitations for the organisms to be included 

 as the etiologic factor. 



Both Streptothrix and Actinomyces are untenable as generic names 

 if we strictly follow the rules of nomenclature, because they are not 

 entitled to priority in the literature which belongs to Nocardia; besides 

 both Streptothrix and Actinomyces are open to the objection that they 

 have not received a sufficiently clear botanical definition and both names 

 have been used in too uncertain a sense in the past. Actinomyces has 

 also, unfortunately, been taken into recent literature with practically 

 two definitions. The objections to Nocardia are as follows: (1) The 

 published definition erroneously states that the branching is "false 

 branching;" (2) the name has not been sufficiently accepted by bota- 

 nists to insure permanency and (3) usage is very much against it, 

 particularly as in some of the recent writings its meaning has been 

 limited to include only a portion of the organisms which surely belong 

 in the genus. Considering the confusion in botanical literature and 

 the uncertainty, and therefore the liability to change which pertains to 

 this nomenclature, we have, as stated in the introduction, chiefly because 

 of usage, and therefore somewhat arbitrarily, tentatively accepted Strep- 

 tothrix as the generic name of the organisms concerned, and streptothri- 

 eosis as the designation of the disease caused by this group of branching, 

 filamentous organisms. In making this decision we are fully aware of 

 the rights of those who favor Actinomyces or Nocardia, and under the 

 circumstances are tempted to introduce a new name (CaHerii) for the 

 genus, together with a full and complete definition. 



Whatever the nomenclature, it is a fact that we have here a group 

 of closely allied vegetable parasites of man and animals, which have 

 the following principal characteristics : 



Branching, filamentous organisms which develop into colonies made up 

 of the organisms and "transformation products." The terminal hypha? 

 may or may not be radially placed on the surface of the colony and they 

 may or may not develop "clubs." The group in general take Gram's 

 stain and several members show acid-fast properties in a varying degree. 



The organisms grow on artifical media, differing in their requirements 

 for oxygen and in pigment production. To a less degree they show other 

 variations in appearance on artificial media. 



The majority of the organisms produce lesions in monkeys, which 

 histologically resemble those found in the human infections and in those 

 of other animal diseases caused by members of this genus. 



This group or genus is closely allied to other genera of somewhat 



