42 
J. C. ARTHUR 
Pacific Coast. It was found at the hot springs on Baranof Island in 
southeastern Alaska. When I began studying the material of this 
collection, through the kindness of Professor Trelease, I felt confident 
that a knowledge of the complete life history would throw light upon 
the evolution or affinities of the Juniperaceous rusts. As the collec- 
tion was made the middle of June it seemed probable that telia might 
be found on the same host later in the season. I wrote to Professor 
C. C. Georgeson of the Experiment Station at Sitka, Baranof Island, 
and to other Experiment Station men in Alaska, and to botanists 
going to Alaska, asking them to look out for such a hypothetical rust, 
but without returns. When Dr. Kern prepared his monograph on the 
Fig. I. Two teliospores, one germinating, and two urediniospores of Gymno- 
sporangium nootkatensis. Drawn Wxth camera luc*da from material sent by Prof. 
H. S. Jackson from Oregon. X 625. 
genus Gymnosporangium in 191 1, he made good use of the ideas 
brought together up to that time, and predicted that telia would 
eventually be found of the foliicolous form, causing no hypertrophy. 
He also predicted that Aecidium Sorhi would be shown to be the aecial 
stage. 
The collection, which finally gave the key to the problem, came 
^ Kern, A biologic and taxonomic study of the genus Gymnosporangium. Bull. 
N. Y. Bot. Gard. 7: 408. 191 1. 
