JEfiANGIE FARDUNJI DASTtfR 221 



Thread." Vertical cracks were present on the inoculated areas and in some 

 cases there was even an exudation of latex in drops. Sections from these areas 

 showed the presence of intercellular hyphge in the tissues, which had turned 

 brown as in the case of naturally diseased tissues. Of the 55 inoculations made 

 only 4 were unsuccessful. 



Inoculations in a similar way were also made on renewing bark and old 

 bark. Fifteen inoculations on the uninjured renewing bark where the cork 

 formation had taken place and 18 inoculations on the uninjured old bark were 

 made ; all these failed. ^\T]en, however, tlie bark was removed thereby exposing 

 the outer green tissues of the cortex, the inoculations were successful. Of the 

 33 made only one failed. The inoculated tissues turned black, became depressed 

 and developed vertical cracks. The blackening of the tissues did not extend 

 beyond the cut and practically remained confined to the exposed green cortex, 

 at least for three weeks, and had not during this period reached the cambium ; 

 only when the bark round the inoculated area was removed, laying bare healthy 

 green tissues, did the infection spread outwards and attack the newly opened 

 tissues. On branches also inoculations failed on the uninjured bark 

 (7 inoculations were made) but succeeded on newly opened green tissues (18 

 inoculations were made). In those cases in which the tissues were wounded 

 almost as far as the cambium, which was itself uninjured, gaping wounds 

 exposing the wood were formed as the result of the inoculation. All these 

 experiments were carried out on mature trees, i.e., trees more than 6 to 7 

 years old. Trees 1 to 5 years old have also been experimented upon and 

 the results have been the same. Six inoculations made on the uninjured 

 thin epidermis have been unsuccessful, but on 19 young trees where the 

 epidermis was injured the inoculations succeeded ; the same results have 

 been produced with saplings a few months old ; in all these cases inocula- 

 tions were made in the same way as described in the first case. In a few 

 cases zoospores were used instead of the mycelium and inoculations on 

 freshly opened tissues have been equally successful. Some of the successful 

 inoculations have also produced sporangia. , 



Morphology of the Fungus in Culture Media. 



This fungus has been growTi in various culture media to induce it to 

 produce oospores ; but all attempts have failed. 



In some agar media sporangia are much bigger than those found on the 

 host plant. In nutrient media they vary from 25 to 51^ in length and 19 to 

 37;i in breadth ; they are terminal, lateral or even intercalar. The number of 

 zoospores liberated by some of these sporangia is as much as 30 ; the size o/ 



