Dodge and Adams: Gymnosporangia on Myrica 25 



place, which is just across the bridge near " the bird-house estab- 

 lishment" at Toms River. Even here it is rare. If the rusts on 

 the bayberry and sweet fern belong to the same species, it is inter- 

 esting to note that the host reactions are somewhat different in 

 the two cases. 



The aecidia on the Myrica are ordinarily very closely crowded 

 on rather definitely limited thickened areas ( PI. 2, f . 1-3 ) . Infected 

 sweet fern leaves are shown in PL 3, f. 1-4. The coiling of the 

 leaves resembles somewhat the effect of insect work, especially 

 such as one sees on sweet fern plants. The aecidiospores from 

 the two hosts appear to be identical so far as size and wall char- 

 acters are concerned. It is possible that they are darker colored 

 in the rust on Comptonia. Our photographs (PI. 2, f. 3, 4) 

 show that the peridial segments may be more persistent and more 

 recurved in the Myrica rust. This may have been due to the 

 difference in the atmospheric conditions prevailing at the times 

 the photographs were taken. Fromme (1. c.) found that spores 

 of Aecidium myricatum had seven or eight germ pores. Profes- 

 sor C. R. Orton has kindly examined our specimens of the rust on 

 Comptonia and Myrica and finds that the peridial cells and aecid- 

 iospores are the same in both forms, although the number of germ 

 pores in the spores of the rust on the sweet fern was not de- 

 termined. 



We have made a number of inoculation experiments with 

 Aecidium myricatum from Myrica with the view to determine 

 the conditions under which the Chamaecyparis may become in- 

 fected. Eleven potted cedars were sprayed with aecidiospores 

 on June 21, 1915, and kept in a moist chamber two days. The 

 plants were then stacked in the greenhouse under bayberry plants 

 heavily infected with the rust. The cedars were sprayed twice 

 each day during the time spores were being shed from the rusted 

 bayberry plants. As yet there are no indications of infection. 

 Reed and Crabill (191 5) have raised the question in connection 

 with the infection of red cedars by the apple rust whether it may 

 not be that the aecidiospores winter over and infect the cedars in 

 the spring. Just why this is assumed or thought possible is not 

 clear in face of the fact that they show in tables of germination 

 experiments that spores germinate in cultures to the extent of 12 

 per cent, in some cases during July. 



