292 DopGE: STUDIES IN GENUS GYMNOSPORANGIUM 
The table shows that eighteen of the twenty-four plants 
inoculated became infected, one of them in fourteen different 
places. Sori matured about twenty months after inoculation, 
except in the case of plants Nos. 907, 908, and 909, where sori 
developed the year following inoculation. It is possible that in 
some cases this species may mature in one year especially where 
inoculations are made as early as April 24. 
In many cases there is but little hypertrophy or distortion of 
the leaves or twigs when the sori are first formed. There is a 
slight bending of the tip of the branch and a cushion-like swelling 
is developed beneath the sorus. After another year a witches’- 
broom of considerable size is formed, or if the main stem is infected 
a slight spindle-shaped swelling occurs. Sori may be foliicolous 
with the primordia in the leaf tissue, but in all cases the mycelium 
penetrates into the wood of the branch. 
GYMNOSPORANGIUM CLAVARIAEFORME 
The telial stage of G. clavariaeforme was obtained from New 
Haven, Connecticut, through the courtesy of Dr. Clinton and 
Dr. Nichols. Several plants of Amelanchier and other pomaceous 
hosts were inoculated May 9-13, 1916. The most abundant 
aecidia were produced on Amelanchier canadensis and A. inter- 
media. If spores are floated on water in damp chambers the per- 
centage of germination is ordinarily about 95 per cent. 
Five plants of Juniperus communis had been obtained from a 
nursery in New Jersey in 1915. They were about one foot high. 
Six smaller plants, three to six inches high, came from Glen, New 
Hampshire. Nine of these junipers were sprayed with spores in 
June, 1916. They were taken from the cold frame March 7, 1917. 
Two plants from New Hampshire were used as controls and showed 
no signs of being infected. Minute sori were discoveted on three 
plants in April. No further inspection was made from May 14 
until September 10. At this time slight swellings along the stems 
of two of the infected plants could be distinguished. Three of the 
nursery plants died before January 7, 1918. The results of these 
inoculations are given in TABLE V. 
