Ethel M. Doidge 



63 



Pathological Histology. 



Infection usually takes place through the nectaries, but the organism 

 sometimes finds its way into the green tissues of the flower and flower 

 stalks through the stomata. 



The rods multiply very rapidly in the intercellular spaces, and it is 

 very noticeable that wherever the intercellular spaces are invaded, the 

 contents of the adjacent cells become plasmolysed and stain very deeply 

 with carbol fuchsin. In sections stained with carbol fiichsin and liaht 

 green these showed up in startling contrast to the normal cells which 

 stained light green and in some of which the nucleus could be plainly 

 seen (Fig. 2). 



Fig. 2. .Section through diseased receptacle, natural infection, drawn with 

 Edinger's projection apparatus. An early stage of infection. 



After the cells are plasmolysed and killed they disintegrate very 

 rapidly and collapse, the original cell outline completely disappears 

 and the diseased area consists of a disorganised mass staining intensely 

 with carbol fuchsin. 



When the receptacle is infected the flowers soon fall, but in some 

 cases not until the infection has spread into the more deep-seated 

 tissues of the ovary, all of which become blackened and disorganised 

 (Fig. 3). 



