DISEASES OF MINOR FRUIT PLANTS 349 



colour. Many are large and white, and are noticeable from a 

 long distance, while others are small and inconspicuous. In 

 typical mature spots there is a straw-coloured central area 

 surrounded by a dark margin. Very often there is a dark centre 

 within the straw-coloured area, or dark blotches, due to the 

 formation of the black macrospores within the tissue, may be 

 scattered over it in an irregular manner. Sometimes long white 

 arms extend beyond the dark border, and, again, the entire 

 spot may be white or straw-coloured throughout. The internal 

 tissue is soft and decayed at first, but this soon dries out, leaving 

 the injured area dry and sunken. The white or straw-coloured 

 area is not due simply to drying of the affected tissue, as is often 

 the case with similar diseases, but comes on while the tissue is 

 still quite firm, and long before it has begun to dry out. In 

 early stages the spots may be olive brown in colour and fairly 

 regular in outline, or they may be white or irregular from the 

 start. The size of the spots increases very rapidly, so that in two 

 or three days what was a small brown spot will have become 

 from two to six inches in length. Even twelve inches is not an 

 unusual length." 



Leaf-Base Rot. 



In Jamaica, S. F. Ashby reports the occurrence of a rot of the 

 leaf-bases, occurring especially in young plants, which is caused 

 by infestation with Phytophthora parasitica. A secondary 

 malodorous bacterial soft-rot is usually also present. The 

 Ripley variety is most susceptible. 



Fruitlet Spot, Black Eye, Black Spot. 



Nature and Distribution. 



For the past twenty years a disease of ripening pineapples 

 has frequently come to notice in the West Indies, in which the 

 fruit appears externally quite normal, but when cut open reveals 

 dark brown or blackish spots situated in the flesh beneath a few 

 or many of the " eyes." The inappropriate names " black heart" 

 and " core rot," sometimes used for this affection, have probably 

 been transferred to it through confusion with the ripe rots due to 

 Diplodia and Thielaviopsis. 



In Antigua the disease is sometimes very common, at others 

 rare or absent. It occurs in St. Kitts, Montserrat, Dominica and 

 St. Vincent, and has been found in pines purchased in Martinique. 

 Similar affections have been described from Jamaica, Queensland 

 and Hawaii ; in the last two countries, associated with species 

 of fungi different from that met with in the West Indies. 



The disease was investigated by A. Howard in 1901, so far as 

 this was possible from transmitted specimens, and, in the absence 



