210 Illinois State Laboratory of Natural History. 
The species now assigned to this genus were formerly sep- 
arated, and a part of them, having the gelatinous material 
more or less columnar, made to form the genus Podisoma. 
The distinction is not properly generic, and at present most 
mycologists unite all the species under the generic name of 
Gymnosporangium. The European species agree in the spores 
having a single septum, and this is usually made a characteris- 
tic of the genus, but some of the American species, otherwise 
similar, have from one to six-celled spores, so that the descrip- 
tion of the genus is necessarily extended to include them. The 
spores are produced in the spring instead of in the autumnal 
months, as are the teleutospores of most Uredinew; but they 
germinate in May and June, hence have not a long period of 
rest. The promycelium is rapidly formed, under the proper 
conditions, from the mature spores, and sporidia are abundantly 
produced. These latter are believed to develop only on species 
of Pomew, and produce the ecidial growths included under the 
so-called genus Restelia. This alternation of growth has been 
several times experimentally shown, but for the purposes of 
this paper the ecidial forms are given by themselves. The 
mycelium of the teleutosporic form is sometimes annual, but 
more often perennial, and produces remarkable gall-like dis- 
tortions upon the host. 
G. macropus, Lk. 
Sporiferous masses aggregated in globose tufts, surrounded 
at the base by a ring formed by the raised epidermis and sub- 
epidermal tissue of the host-plant, orange-yellow, cylindrical, 
acuminate, half an inch to an inch long, or at times longer; 
spores ovate-acute, two-celled, generally constricted at the sep- 
tum, and with a papilla at the apex, 15-20 by 46-60 »; promy- 
celia generally four from each cell. Mycelium annual, produc- 
ing globose or reniform knots in the smaller branches. On 
leaves and smaller branches of Juniperus Virginiana. (Farlow, 
(tymnosporangia‘of the U.8., p. 13.) 
On Juniperus Virginiuna: Union, May 15, 4705; Cham- 
paign, March 16, 2465. 
