28 



Mycologia 



germination of the aecidiospore of G. macropus than we have 

 with Aecidium myricatum, yet they assume that the spores may 

 winter over and germinate in the spring, since they were unable 

 to obtain artificial infections of red cedars. 



Harshberger (1902) has made a study of the behavior of the 

 mycelium of G. Ellisii in the tissues of Chamaecyparis. He finds 

 an abundance of intracellular hyphae in the cortex, soft bast, wood 

 cambium and tracheids, as well as in the medullary rays, and 

 believes that the mycelium residing in the wood cambium and 

 soft bast is responsible for the increased thickening of the annular 

 rings. Farlow (1880) has very adequately described this Gym- 

 nosporangium and figured very characteristically a small witches'- 

 broom and a germinating teleutospore. Our figure 5 in plate 2 

 shows the sori in the dried conditions. We find that they do not 

 swell up to such a great extent when moistened as do sori of most 

 Gymnosporangia. The promycelia are usually quite sharply bent, 

 as appears in Text-figure 1, b. 



The perfection of methods by which seedling cedars may be 

 easily infected should afford a better opportunity for studying the 

 behavior of both the host and the fungus in their mutual rela- 

 tionships. The evidence is suggestive that G. myricatum also go 

 to the sweet fern, but in view of the very complex interrelations 

 which have so far been found between the hosts of the species of 

 Gymno sporangium and their roesteliae, a positive conclusion can 

 only be reached by actually demonstrating the infection of the 

 sweet fern by G. Ellisii. 



Columbia University, 

 New York City. 



LITERATURE CITED 



Arthur, J. C. New species of Uredineae. Bull. Torrey Club 33 : 27-34. 8 F 



1906. 



Clinton, G. P. Report of the botanist for 1907. Connecticut Agr. Exp. Sta. 



Rep. 31 : 339-396. pi 17-32. 1908. 

 Dodge, B. 0. The effect of the host on the morphology of certain species of 



Gymnosporangium. Bull. Torrey Club 42: 519-542. pi. 28, 29. 13 N 1915. 

 Farlow, W. G. The Gymnosporangia or cedar-apples of the United States. 



Anniv. Mem. Boston Soc. Nat. Hist. [i-30. pi. 1, 2]. 1880. 

 Fromme, F. D. A new gymnosporangial connection. Mycologia 6: 226-230. 



26 S 1914. 



Harshberger, J. W. Two fungus diseases of the white cedar. Proc. Acad. 

 Nat. Sci. Philadelphia 44: 461-504. pi. 32, 33. My 1902. 



