14 FREDERICK EBERSON 



lucent colonies which become white in three days. Bouillon is clouded slightly 

 and sediment produced. Visible acid produced in sugar broth. 



B. CERU MINIS 



From normal ear. Long, thin, curved organism. Gram-positive, polar 

 bodies. Bouillon remains clear with sediment. Neutral or alkaline reaction 

 in sugar broth. Avirulent. 



DIPHTHEROIDS FROM THE EAR 



Diphtheroids of the ear have been made the subject of a very valuable paper 

 by Alice Hamilton. In a study of over 50 cases of otitis media and scarlet 

 fever she succeeded in differentiating 2 groups of organisms. 



GROUP 1. Includes diphtheroids with the following characters : Short rods, 

 gram-positive (weakly staining). Abundant growth on agar. Ferment dex- 

 trose and saccharose but not maltose or dextrin. Nonpathogenic. 



GROUP 2. Long, barred or granular, often clubbed. Gram-positive, scanty 

 growth on agar. Ferment dextrose and maltose, but not saccharose. Often 

 virulent for guinea-pigs. 



The pathogenicity of these organisms is altogether different from that of the 

 diphtheria bacterium inasmuch as diphtheria antitoxin did not protect against 

 them. Hamilton's studies showed also that the organisms isolated from otitis 

 undoubtedly have some bearing on the disease since vaccine treatment had a 

 marked effect on opsonic determinations. If we compare this type (Group 2) 

 with the B. auris described by Graham Smith it appears that we have the 

 same organism. Unfortunately the work of the last named author does not 

 mention virulence tests and the strains were too few in number to merit com- 

 parison. We are safe, however, in recognizing that the diphtheroids found in 

 the ear are not of the same type and that in cases of otitis media and post- 

 scarlatinal infections another species, not necessarily of etiologic significance, 

 seems to predominate. The name Coryn. auris (Graham Smith) is proposed. 



B. CERUM1NIS 



This organism has been observed also by Dr. Dwyer, of this laboratory. 

 This organism fails to ferment any of the sugars and differs from C. Hofmanni 

 in morphology as well as its behavior in broth which remains clear, with sedi- 

 ment. The name should be Coryn. ceruminis (Graham Smith) comb. nov. 



There remains for consideration the diphtheroids of Hamilton's Group 1. 

 These organisms differ from C. hoagii (Morse) only in the absence of a salmon- 

 pink pigment. In all likelihood these strains conform to this type. Besides 

 these ear diphtheroids, there seems to be a variety which is characterized by 

 vigorous fermentative properties in a number of sugars. Two such strains have 

 been isolated by the writer. A description follows : Gram-positive, small rods, 

 abundant, white glistening growth on agar, no spores. Form large amounts 

 of acid in dextrose, lactose, saccharose, maltose, mannite, and dextrin, but do 

 not split raffinose. Acidity titrations with N/20 NaCH after 48 hours' incuba- 

 tion were as follows : 



Dextrose Lactose Saccharose Maltose Mannite Dextrin 

 Strain 1 3.2 3.5 3.9 4.0 2.8 2.3 



Strain 2 5.0 3.6 4.4 4.7 2.6 2.0 



These strains were obtained from cases of otitis media. This species is similar 

 to the diphtheroides brevis described by Graham Smith. It is suggested that a 



