16 FREDERICK EBERSON 



very readily from "blackheads" without the use of special mediums. It is 

 believed by some that "blackheads" are to be looked on as a stage of acne. In 

 order to adhere to the rules of priority we should designate this diphtheroid 

 as follows; Coryn. acnes (Gilchrist) comb. nov. Cultural studies with this 

 organism were made by Siidmerson and Thompson in 1910. They confirmed 

 Sabouraud's findings as to the suitability of highly acid mediums for culti- 

 vating C. acnes. One part horse serum to 3 parts of 3% nutrient agar (4.0) is 

 recommended as a culture medium for isolation. Ordinary glucose agar may 

 be used just as well, however. Fermentation studies show that the organism 

 ferments dextrose, saccharose (slight), maltose, mannite and inulin. Raffinose 

 is fermented by 1 strain and not by another. The authors suggest raffinose as 

 a means for differentiating 2 species. Several strains studied by the writer 

 formed no acid in raffinose and in dextrin. 



Virulence tests were made on guinea-pigs and mice. Only the latter suc- 

 cumbed to an injection of 4 loopfuls of a 5 day culture. On necropsy the ani- 

 mals showed a greatly enlarged spleen, enlarged and congested mesenteric glands, 

 enlarged, soft and anemic kidney, congested suprarenals and an enlargement 

 and congestion of the axillary and inguinal glands. 



B. PSEUDOTUBERCULOSIS OVIS PREISZ (NOCARD) 



This organism was originally isolated by Preisz and Guinard from necrotic 

 areas in the kidney of sheep. Later, Preisz described the organism more fully. 

 It is gram-positive, nonmotile and club-shaped. On serum it produces a heavy 

 moist growth with golden-yellow pigment. Toxin production is attributed to 

 the organism and is fatal for guinea-pigs, rabbits, goats and sheep. In guinea- 

 pigs, intraperitoneal inoculation gives rise to an orchitis. In larger animals 

 there is produced a pseudotuberculosis which can be differentiated from true 

 tuberculosis by histologic study of the pseudotubercles which do not show the 

 characteristic giant cells. In a recent paper by Hall and Stone this organism 

 was found to produce suppurative processes throughout the lymphatics in guinea- 

 pigs. The toxin which is elaborated by the bacterium resembles but is not iden- 

 tical with that of diphtheria, yet is partially neutralized by diphtheria antitoxin. 

 The authors found that the organism was hemolytic in blood agar which did 

 not contain an excess of fermentable carbohydrate. Dextrose and maltose were 

 fermented, but glycerol was not attacked, thus differing from C. striatum which 

 ferments glycerin and like the B. pseudotuberculosis ovis Preisz produces a 

 yellow pigment. Three strains of this organism (horse, sheep, calf) which were 

 sent to the Museum of Natural History by the writer were tested for acid pro- 

 duction along with the other diphtheroids. The strain from the calf produced 

 more acid in dextrose and dextrin than either of the other two. The detailed 

 results of the tests were as follows : 



/ N/20 acid s 



Dextrose Lactose Saccharose Dextrin 

 (Horse) 1.8 0.6 0.3 0.7 



(Sheep) 0.9 0.3 



(Calf) 2.4 0.4 0.3 1.7 



Coryn pseudotuberculosis (Preisz) comb. nov. is perhaps the correct desig- 

 nation. 



B. HOAGII 



Morse described this type in 1912 as representing one of the groups which 

 she established as the result of a biometrical study of 295 strains. The char- 

 acters may be summarized as follows : Medium-sized bacterium showing solid 



