RIPE ROT. 



[See Coloured Plate, Frontispiece. ] 



IN December, 1891, and January, 1892, I conducted a number of 

 experiments with the common ripe rot of the apple, then generally 

 known among mycologists as Gloeosporium fructigenum* '. In comment- 

 ing on this disease in the April number of this Gazette for that year, I 

 said : " A sterilised needle bearing a few bitter-rot spores is thrust 

 through the skin of a peach, plum, nectarine, pear, cherry, grape, or 

 mango, and after five days, from the invisible puncture thus made, a 

 diseased spot appears which passes through all the stages just 

 described in the case of apple. I have observed the disease occurring 

 naturally on the peach, grape, pear, and mango." 



In the same year Dr. Halsted, of New Jersey, U.S.A., carried out 

 a similar set of experiments with the same general results. Dr. Halsted 

 made a larger number of cross inoculations than I, and his results were 

 even more suggestive than mine. I give some of his results in his 

 own words : 



" The work, so far as it has gone, and it is far from being completed, may be 

 represented graphically by a diagram (Fig. 2), in which the several fruits. 



Fig. 2. Diagram showing inoculations. 



1, Apple ; 2, Peach ; 3, Banana ; 4, Pepper ; 5, Bean ; 6, Persimmon ; 7, Lemon ; 8, Watermelon - 

 9 Quince; 10, Citron; 11, Grapes; 12, Tomato ; 13, Egg-plant ; 14, Pear ; 15, Squash. 



treated are arranged in an oval, and the successful inoculations are shown by 

 lines drawn from the fruit yielding the rot naturally to the ones which are 

 susceptible under the conditions of inoculation. 



" There are two sorts of lines, the dotted ones, representing the Gloeos- 

 poriums, or light-coloured fungi, and the solid ones, the Colletotrickums, which 

 are usually dark, as above stated, because of the stiff, black bristles. The 

 arrow shows the direction in which the inoculation has gone. 



* Now more correctly called Glomerella rufomaculans (Berk.), Spaulding and Von Schreiik.. 



