238 
Mycologia 
14. The aecia developed rapidly on about fifty of the leaves, 
and were mature in a few days. The aecia were the deep red- 
dish-yellow form collected abundantly in Nova Scotia in several 
regions beside Pucciniastrum Myrtilli on Vaccininm canadense 
and V. pcnnsylvanicum Lam. which has passed as Peridermium 
Pcckii Thiim. but which Arthur regards as distinct. - 
This confirms the life history of this species as established by 
Clinton (Report Conn. Agric. Exper. Sta. 1909-1910, p. 719 and 
MS.) who sowed aeciospores from Tsiiga catiadeusis on Gaylus- 
sacia baccata (Wang) C. Koch, and produced the uredinia of 
Pucciniastriiin Myrtilli. 
]\Iel.\mpsora Medusae Thiim. 
Leaves of Popnlus grandidentata Michx. bearing abundant 
telia of this rust were placed in a moist chamber and the telio- 
spores gave excellent germination in a few days. A sowing on 
two plants of Tsuga canadensis (L.) Carr, was followed on both 
plants by pycnia in about a week, and later by aecia. 
On July 18, 1912, the cones of a considerable area near Pictou 
were found to be infected by Caeonia Abietis-canadensis Far!., 
about one half of the cones showing infection. The place was 
visited about ten days later and the uredinia of Melampsora Me- 
dusae were abundant on the leaves of Popnlus grandidentata 
which grew near and beneath the infected trees. These experi- 
ments and observations confirm the cultures of last year.® 
Melampsora arctic.\ Rostr. 
Teliosporic material from Salix (species undetermined) was 
placed in a moist chamber until the teliospores germinated when 
it was suspended above Abies balsamea on June 10. Pycnia were 
noticed on June 24 followed by aecia. This experiment confirms 
the cultures of the previous season.^ 
"See Mycologia 4: 184. 1912. 
* See Mycologia 4: 188. :gi2. 
‘See Mycologia 4; 187. 1912. 
