66 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. uxIx. 
suffer severely year after year, the land being under a two- 
course rotation—wheat being one of the two crops grown 
annually, The field was low-lying, well sheltered, and badly 
drained. After a spell of very cold weather in the year 1899, 
on examination uredospores were found in plenty. 
6. In a rust-infested field near Shebin el Kanater, after a 
spell of keen frost during January 1898, only teleutospores 
could be found. The following year the wheat crop was 
almost free from rust. 
7. A field near Galiub in 1897 was badly infested. After 
the cold winter of 1898-99 the crop suffered but little. 
8, Near the Barrage, Cairo, three fields were badly infested 
with rust during 1897-98. After the cold weather of the 
two following winters the wheat crops suffered just as much. 
Barberry plants were found cultivated in a neighbouring 
garden, and this may account for the flourishing condition of 
the pest. 
9, In Bulag-el-Dakrur :— 
(a) One well-sheltered field showed rust (uredo stage) 
in the middle of winter during the year 1899—a 
year hardly a favourable one to the fungus. The 
crop was an exceptionally early one. 
(6) Another field, not a mile distant from the former, 
though it did suffer with rust during 1897, was 
quite free from rust during the two following 
seasons. The disappearance of the disease cannot 
be accounted for unless it was due to the severity 
of the weather. During these two winters the 
potato crops had been completely destroyed by a 
several-nights’ frost. 
10, In the Ghizeh province five observations were made. 
During 1897 all five fields suffered heavily. | 
In 1898, after a dry, cold winter, two fields particularly 
exposed were practically free from rust, 
During 1899-1900, after an exceptionally cold winter, one 
of the most exposed fields was found to be suffering badly 
with ‘rust in the spring, the others being practically free, 
This was the only contradictory observation I made, and 
infection in this case may have been brought about by seed. 
11. A sheltered field of wheat in Matarieh during the cold 
winter 1899-1900, on ‘examination proved to be suffering 
