DISEASES OF PLANTS. 471 



disease is easily produced in rabbits by inoculation with 

 the perfectly clear and apparently entirely sterile serum 

 from other cases. Also dogs and men react to the inocu- 

 lation (C. B. XXIII, 866). 



Noma. 



Petruschky has found diphtheria bacteria together with 

 pseudodiphtheria bacteria in two cases of noma faciei, 

 which he cured with diphtheria antitoxin (Deut. med. 

 Wochenschr., 1898, 600). 



Epidemic Parotitis. 



Laveran (Compt. rend, de la soc. de Biolog., 1893, 

 95) found diplococci in the blood and organs in 67 out of 

 92 cases of mumps. Thej^ kill mice and cause in rabbits 

 and dogs a transitorj^ orchitis, which often is associated 

 with mumps also. Mecray and Walsh (C. B. xxi, 68) 

 have made similar observations. The cultures were de- 

 scribed by the latter authors as very similar to those of 

 very poorly growing ]\Iicroc. pyogenes. 



Diseases of Plants. 



In spite of the efforts of numerous investigators to de- 

 monstrate bacteria as the cause of diseases of plants, we 

 possess little knowledge which is free from objection in this 

 field. The botanist Alfred Fischer takes an especially 

 skeptical stand regarding the statements so far made (C. B. 

 L. V, 279), while Erwin Smith, who has himself done much 

 work in this field, is much more optimistic in his judg- 

 ment, and considers the connection of bacteria and disease 

 to have been demonstrated in a whole series of instances. 

 He enumerates some of the varieties of bacteria which are 

 most certainly pathogenic for plants (C. B. L. v, 271 ; in 

 the same place the literature is given). We refer to the 

 following : Bacillus amylovorus Burrill (cause of a dis- 

 ease of apple and pear trees), Bacillus oleae Savastano 

 (tuberculosis of the olive tree). Bacillus hyacinthi- 

 septicus Heinz, Bacillus tracheiphilus Erw. Smith (in- 

 jurious to various cucurbitacese). Bacillus solanacearum 



