256 



generally of the citizens of the city. On a field trip in November, 1899, 

 we noticed the extraordinary abundance and great size of the galls that 

 infested the cedars in yards and pastures. In commenting upon this 

 Prof. Thomas said that never before had he seen them in such numbers 

 and of such large size, some of them being at that time as large as wal- 

 nuts. The infection was very general. Every cedar fx'om the small seedling 

 to the tall tree was fairly loaded on every twig and branch with the choco- 

 late-brown galls. Just what caused this unusual abundance is not so easily 

 discovered, but perhaps the folloAving record of the weather for .July and 

 August and the first days of September, 1899, may throw some light on 

 the matter. From observations made the following year it was found that 

 the aecidiospores began to ripen al)out July 20. Beginning, tlien, with 

 July 28, we have tlie following: 



July 28, 1899 Rain 



August 2, 1899 Rain 



August 5. 1 899 Rain 



August 8, 1899 Rain 



August 2.5, 1899 Rain 



September 0. 1899 Rain 



Six heavy rains, followed Ity Intervals of from three to sixteen days of 

 warm, fair weather, as shown by the weather reports kept in the city, 

 the very best conditions for tlie distribution and germination of the 

 aecidiospores on the cedar. "What other factors may have entered into 

 this general infection we ai"e unable to say. 



The conditions the following spring (1900) bore out fully the promises 

 of the previous fall. The warm rains of the latter part of April and 

 throughout May brought forth the yellow gelatinous masses of teleuto- 

 spores in abundance. So numerous and large were the galls that the limi s 

 of the trees bent beneath the burden and the large yellow masses could be 

 seen for long distances. The warm sun of the days following the rain 

 dried up the gelatinous masses, causing the teleutospores to germinate and 

 produce countless numbers of sporidia, Avhich were carried far and near 

 to the apple trees of the city and surrounding country. How perfect tlie 

 weather conditions of that spring Avere for the dissemination of this 

 fungus, the following record will shoAv: 



