DopGE: STUDIES IN GENUS GYMNOSPORANGIUM 289 
July 1, 1915, and any new galls that appeared were marked with 
tags. The heights of the plants were taken in February, 1914, and 
each spring since that date. These precautions enabled me to 
obtain evidence relating to the length of life of the galls, especially 
of G. globosum, which has been assumed to be perennial, although 
records bearing on this point appear to be meager. Hawthorns 
bearing aecidia of G. globosum were grown in the greenhouse at the 
same time and this fact required that infections be made with 
teleutospore material from galls that appeared on the cedars later, 
since the smaller galls of G. globosum and G. macropus are not 
always so characteristic as to be easily distinguished. The results 
are given in TABLE II. 
TABLE II 
INFECTION OF THE RED CEDAR WITH G. macropus 
Height of cedars, inches 
N | Date of | Results, number Ss 
o- Feb., Feb. Feb., Feb., | inoculation of galls } pores matured 
| tOr4 1915 1916 19*7 
O14 | 
401 II 16 24 z July 13 fs) 
403 7 12 206 35 June 13 2 | March 17, 1916 
504 6 10 I5 23 June 7 3 1916 
4II 14 24 39 53 June 22 ts) 
414 16 24 39 gs June 20 2 Ma 18, 1916 
415 9 13 rg 20 June 28 2 April 2, 1916 
417 16 at 34 48 June 20 ra) : 
403 7 12 26 35 I9I5 3 April 14, 1917 
july . 2 
407 I2 22 35 50 Aug. I 6 April 24, 1917 
416 pas) 14 17 24 June 5 | 2 April 25, 1917 
418 yg ? 20 42 June 10 I March I, 1917 
The last date upon which the plants were exposed to natural 
infection was in the summer of 1913. The point at which the 
lowest gall, for example on plant No. 403, appeared was five inches 
above the tip of the main stem of this plant February 1, 1914, as 
shown by the records of measurements. The cultures, especially 
those made in 1915, prove that Heald’s conclusions were correct 
as regards the time required for the maturity of the rust. There 
were fourteen galls on these four plants; they were for the most 
part comparatively small, bearing from one to five sori. 
