186 PHYT0PHTH0PA PARASITICA. 



were placed in exactly similar conditions. Male flowers took the 

 inoculation in a day, turning brown and then black. The branched 

 stamens were cobwebbed by hyphae, rich in sporangia. Green 

 fruits in two days turned black and became soft at the point of ino- 

 culation. The disease then spread over the whole fruit and caused 

 it to rot. Sporangia and " resting " conidia were abundantly 

 produced. The attack was not confined only to the outer soft por- 

 tion of the pericarp, but the hard woody portion also was found 

 to contain stray strands of hyphae which made their way through the 

 lignified cells by means of a very fine projection which bored through 

 the hard cell wall (Plate II, Fig. 4). A fine web of mycelium was 

 found in the cocci between the seed and the endocarp. The fungus 

 extended there through the lignified cells or, as often happened, 

 through the dissepiments of the loculi. The fleshy outgrowth on 

 the seed, the caruncle, was then attacked by the hyphae and 

 through it the immature seed. The hyphae completely filled the 

 caruncle. They invariably traversed the cells through the pits in 

 their thick cellulose walls. The course of the hyphae in the seed 

 coat was difficult to trace. Inoculations on dried fruits invariably 

 failed. 



Though in the laboratory fruits and flowers are so virulently 

 attacked by the parasite, still in nature they have been found to be 

 entirely immune from its attack. The cause for this is solely to be 

 attributed to the climatic conditions prevalent at the time of fruit- 

 ing. The rainy (Kharif) crop fruits in October, November and 

 December, a period when the fungus has completely disappeared 

 from the fields. The winter (Rabi) crop fruits in April and May, 

 when the temperature is too high for the fungus to grow. 



The following experiments were undertaken to see how far soil 

 inoculations prove successful. 



On account of the frequent showers of rain in April and May 

 last year (1912) the disease broke out early in June in self-sown plants 

 in the castor plots of the previous year. About fifty to sixty per cent, 

 of the seedlings were diseased. All the seedlings were removed from 

 the field early in July. On the 17th three pots (Lot A) were filled 



