Fromme: A New Gymnosporangial Connection 227 
and Gym. Ellisii not only carries the aecial hosts of the genus to 
a group outside of the Rosales but to one that is apparently widely 
separated from them in phylogeny, the Myricales being the fourth 
order of Dicotyledoneae in Engler and Prantl’s Natiirliche Pflan- 
zenfamilien, while the Rosales is the eighteenth. This is not in 
itself so surprising, as similar wide ranges of hosts are known in 
other rust genera. It shows, however, that the species of Gym- 
nosporangium are a much less restricted group than was formerly 
supposed, and suggests the possibility that the aecial hosts of other 
unconnected species may also be found in groups other than 
Rosales. 
The aecium of Aec. myricatum is of the cupulate type, a type 
which has only recently been recognized as occurring in the genus 
Gymnosporangium and is at present known in but two species, 
G. Blasdaleanum and G. Sorbi, in addition to the one under dis- 
cussion. The remaining species of Gymnosporangium have aecia 
of the cornute type, which had for a long time been considered 
exclusively diagnostic of the genus. G. Ellisii in addition to its 
cupulate aecia has the hamaspora or phragmidium type of telio- 
spores, in which the teliospore has commonly more than two cells, 
the variation being from two to five. G. Blasdaleanum also has 
cupulate aecia and teliospores of the hamaspora type, but G. 
Botryapites has teliospores much like those of the two foregoing 
species and cornute aecia. The telial stage of G. Sorbi, of which 
the aecia are cupulate, is unknown. 
The suggestions that have led to the establishment of this con- 
nection were obtained from a morphological study of the aecium 
supplemented by field observations on the association of hosts. A 
quantity of the aecium on Myrica carolinensis was collected at 
Woods Hole, Mass., in 1912, by the writer, for a morphological 
study. The evident germ pores of the aeciospores and other fea- 
tures suggested that it might possibly be the aecium of a Gymnos- 
porangium. In May of the following year, 1913, Dr. R. A. 
Harper, Dr. B. O. Dodge, and the writer made a trip to the pine 
barrens at Lakehurst, N. J. Both Gym. Ellisii and Gym. Botrya- 
pites were found there in abundance on the southern white cedar, 
Chamaecyparis thyoides , and three possible alternate hosts, Ame- 
lanchier canadensis, Aronia arbutifolia, and Myrica carolinensis 
