60 



Mycologia 



in drop culture, and gave abundant and vigorous germination 

 after twelve hours. Sowings were at once made June 29 on 

 two plants of Arabis in the rosette stage, grown from seed sent 

 by Mr. Bethel from Colorado. One plant flowered later and 

 showed no evidence of infection. The other plant gradually 

 developed numerous lateral buds, forming a compact mass of 

 small rosettes. This rather abnormal development seems to in- 

 dicate a probable infection, but the proof must await the elon- 

 gation of the stems at flowering time next spring. 



The credit for detecting the probable connection of these aecial 

 and telial forms is to be shared by Mr. A. O. Garrett and Mr. E. 

 Bethel. On packet 75 of the Fungi Utahensis, Aecidium mono- 

 icum on Arabis Drummondii, Mr. Garrett adds the note, " ap- 

 parently connected with a rust on Trisetum subs pic atum." This 

 collection was made July 22, 1905, and in a letter dated April 

 30, 1906, he writes : " On July 22 I made a collection of aecidia 

 on Arabis Drummondii. The plants were in an open place on 

 the mountain side between spruce timber on either side. On 

 August 21 I returned to the spot to hunt for the alternate form 

 of the A. mofioicum. Upon reaching the locality I found a plant 

 of Trisetum subspicatum, and on it I found teleutospores [dis- 

 tributed in Fungi Utahensis 194]. Immediately next to it I 

 found a dried up plant of A. Drummondii with abundant aecidia. 

 Looking further, I found that wherever I found the III, I found 

 I, although in a few cases I found I without running across III." 

 It should be borne in mind that these observations were made 

 in the arid region of the Rocky mountains, where juxtaposition 

 is more significant than in more humid regions. Mr. Bethel 

 made similar observations at various times in Colorado, and is, 

 moreover, convinced from his field studies that the same spe- 

 cies of rust occurs on Koeleria and Stipa. This may be true, 

 and collections in the herbarium seem to justify the opinion, at 

 least for Koeleria, but cultures are yet wanting, material for 

 which should be gathered in late summer or autumn, and not in 

 spring. In a letter dated April 9, 191 1, Mr. Bethel makes the 

 significant statement : The Koeleria and Trisetum rusts have a 

 strange way of disappearing. It is almost impossible to find 

 them in the spring. I brought home plants of both Koeleria 2ind 



