MODE OP 

 NATURAL IN- 

 FECTION. 



IMMUNE AND RESISTANT SPP. AS 



TESTED BY ARTIFICIAL 



INOCULATION. 



GENERAL REMARKS. 



BIBLIOGRAPHY. 



Insects during 

 fertilization of 

 flower, punc- 

 ture by insect 

 stings, bites, 

 etc. 



Cydonia Japonica, atomizing flowers. 



Peach, nearly immune. (Arthur.) 



Grape, 



Mulberry, 



Corn, 



Potatoes, 



Bean, 



Onion, 



Wheat and oats. 



Natural immunity of diff. species of 

 pear family lost when subjected to 

 artificial inoculation. 



A general infection usually 

 affecting the more succulent 

 parts of tree, recognized by 

 the blackened or burnt ap- 

 pearance (hence name fire 

 blight) of part affected, also 

 by gummy exudate. 



Burrill : 3d 111. Rep. Agri. 

 1890. Amer. Nat. VII 

 (1883), 319. Trans. 111. 

 Hort. Soc. 1877, 1878. 111. 

 Indus. Univ. Rep. 1882. 



Arthur : 4th, 5th and 6th 

 N. Y. Agri. Exp. Rep. 

 Proc. Acad. Sc. Phil. 1886. 

 Amer. Nat. XIX (1885), 

 1181. Proc. Amer. Ass. 

 Adv. Sc. 1885. Bot. Gaz- 

 ette X, 343. 



Waite : Unpublished work 

 of U. S. Ag. Dept., Div. of 

 Veg. Path. 



1 Detmers : Ohio Bull. No. 

 6, 1891. 



Stomata and 

 roots. 



Zea mays. 



Triticum vulgare. 



Sorghum vulgare (some varieties). 



Some varieties of sugar sorghum 



(Kellerman and Swingle). 



Disease affects principally 

 leaves and their sheaths, also 

 the roots. Parts affected 

 show a crimson red patch, 

 usually circumscribed, not 

 causing a rupture on the sur- 

 face. Cell contents degen- 

 erate, walls turn red. 



Burrill: 8th Rept. Soc. 

 Prom. Ag. Sc. 1887. Micro- 

 scope, Nov. 1887. 



Kellerman and Swingle : 

 Kans. Rep. 1887 and 1888. 

 Bull. No. 5, Dec. 1888. 



See J. of M. V. 195 for 

 discussion of a sorghum dis- 

 ease by Comes. 



Artificial in- 

 oculation suc- 

 ceeded without 

 puncture. 



Closely allied to sorghum 

 germ in appearance and by 

 its pathological changes in 

 tissue. Dark brown discolor- 

 ations on leaves. Where root 

 is affected whole plant suffers 

 in loss of nutrition. 



Burrill: 3d. 111. Rep. 1890. 

 Am. Assoc. Ad. Sc. 1889. 

 Soc. Prom. Ag. Sc. 1889. 

 111. Bull. No. 6, 1889. 



Duncanson : Nebr. Acad. 

 Sc. II. 



All double red varieties and some other 

 double varieties immune under nat- 

 ural conditions, but lose immunity 

 when artificially infected. 



Disease restricted in its 

 spread throughout tissue, 

 causing a degeneration of 

 primary cell wall and cell 

 contents, forming a gummy 

 exudate, yellow in color. 



Wakker : Bot. Cent. XIV 

 (1883), 315. Arch, neer- 

 land. XXIII (1888), 1. 



Disease pro- 

 duced arti- 

 ficially from 

 pure cultures. 



From description of disease 

 and of germ, this disease 

 appears to be distinct from 

 Wakker's malady. Decom- 

 position of affected parts with 

 formation of foul-smelling 



Heinz : Cent, f . Bakt. 1889, 

 Bd. IV, S. 535. 



Growing point 

 (?) Savastano. 

 Stomata and 

 lenticels 

 (Prillieux.) 



Peach, plum, apricot, grape, fig, pear, 

 apple, bitter orange, lemon, rose, and 

 several coniferous trees. 



Bacteria cause destruction of 

 tissue and formation of spaces 

 in tissue. This induces sec- 

 ondary local growth and 

 causes an internal hypertro- 

 phy in bark which finally 

 produces local death of tissue. 



Savastano: Ann. d. R. 

 Scuola Sup. d'Agric. in Por- 

 tici, Vol. V, fasc. IV, 1887. 



Cavara : Monograph, 

 1889. 



Prillieux : Monograph, 



1890. C. R. Acad. CVII 

 249. 



Pierce: Journ. of Myc. 



1891, 140. 



