432 



SCIENCE 



[N. S. Vol. XXXIX. No. 1003 



name tlie disease organism has since been 

 known. " Provisional " because Thaxter him- 

 self expresses his doubt as to the correctness 

 of referring the organism to the genius 

 Oospora, remarking that the genus Oospora 

 as given by Saecardo has no scientific value. 

 We had occasion to carefully study this 

 organism recently, and from our observations 

 desire to rectify the nomenclature. 



From Saccardo's interpretation of the genus 

 Oospora, and from its numerous species, we 

 must consider it as a fungus pure and simple, 

 a hs^phomycete of the Mucidineae- A mero- 

 sporse. The organism of potato scab proves 

 not to be a fungus. It differs in morphologi- 

 cal characters considerably from what is our 

 present conception of an Oospora. Mr. G. C. 

 Cunningham at the meeting of the American 

 Association for the Advancement of Science 

 in Washington, D. C. (1911), expressed his 

 opinion that the potato-scab organism belongs 

 to the "higher bacteria" and he proposes to 

 place it in the genus Streptoihrix. We are 

 also inclined to regard it as a Schizomycete of 

 the filamentous kind, belonging to the Chlamy- 

 dobacteriacese. On endeavoring to place the 

 organism in its proper genus, we found our- 

 selves confronted by one of the most perplex- 

 ing problems of botanical nomenclature, which 

 promises a rich harvest to those who are fond 

 of such study. 



At first we considered Streptoihrix Cohn» 

 the correct genus, but found later that Cordap 

 in 1839 founded this genus for another hy- 

 phomycetous fungus of which 8. fusca was his 

 species. Hence, according to the Vienna 

 rules, this name was no longer available for 

 another plant genus. Saecardo still considers 

 this name as given by Corda valid, including 

 four species all of which are distinct from our 

 organism. Furthermore, Streptothrix, as 

 erroneously used by Cohn, possesses no 

 " sheaths," whereas our organism does, how- 

 ever delicate they may appear. 



lAnn. Eep. Conn. Exp. Station for 1891, p. 

 153. 



2 Beitrdge zur Biol. d. Pfiamen, Heft 3, pp. 186 

 and 202. 



3 ' ' Praehtflora europ. ScMmmelpilze, ' ' p. 23. 



Other names such as Cladothrix, Nocardia 

 and Actinomyces have also been loosely used 

 for members closely related to the organism 

 of potato scab. Cladothrix is out of the ques- 

 tion owing to its false branching and ciliate 

 spores. 



Actinomyces was established by Harz 

 in 1878* and his description undoubtedly 

 shows generic relationship to our organism. 

 Harz describes A. iovis as causing " lump 

 jaw" or actinomycosis. 



Homer Wright, M.D.," pleads in favor of 

 the name Actinomyces for use only in connec- 

 tion with the organism causing actinomycosis, 

 and suggests that all other organisms of this 

 genus should be knovm as Nocardia " because 

 the use of the generic term Actinomyces for 

 them logically leads to giving the name 

 actinomycosis to those eases of suppurative 

 processes due to infection with certain mem- 

 bers of the group." This point of view is 

 opposed to even the most elementary concep- 

 tion of botanical nomenclature. 



Now Nocardia is the name at present in 

 use by Saecardo for members of our group of 

 organisms.* It was established by Trevisan 

 in 1889; "he considered the generic name 

 Actinomyces untenable because the generic 

 name Actinomyce (without the terminal ' s ') 

 was given by Meyen in 182Y to a fungus 

 (Eydrotremellince (Cams)) described by him 

 ('Actinomyce Horhelii')."'' According to 

 Article 5Y of the International Eules of 

 Vienna, it is distinctly laid down that two 

 generic names, even though differing by one 

 letter only, are to be regarded as distinct, 

 which applies in this case. 



Hence Nocardia Trev. is untenable and Ac- 

 tinomyces Harz must stand for these organ- 

 isms. The organism of potato scab properly 

 belongs to this genus; in consequence I feel 

 justified in correcting the nomenclature as 

 follows : 



* Jahresb. Miinchener Central Tierarzneischule. 



^Journal Med. Bes., Vol. VIII., May, 1905, 

 No. 4. 



9 Saecardo, "Sylloge, etc." VIII., p. 927. 



7 Linnsa, Vol. 2, pp. 433. 



