26 
Mycologia 
their aecia on Abies balsamea, so the question arises whether they 
are distinct or should be included under one species. To obtain 
cultural evidence bearing on this matter, the following experi- 
ments were made. 
The aeciospores of Uredinopsis mirabilis obtained by the ex- 
periment just described were placed in distilled water, and by 
means of an atomizer were sown on the following ferns on June 
14th: Onoclea sensibilis L., Aspidium Thelypteris (L.) Sw.. 
Osmunda Claytoniana L., O. regalis L., Phegopteris Dryop- 
teris (L.) Fee. Uredinia were noticed on June 21st on Onoclea 
sensibilis and soon became abundant. There was no infection of 
the other ferns. Another sowing on June 16th of culture aecio- 
spores on Onoclea sensibilis, Asplenium Filix-femina (L.) Bernh., 
Osmunda Claytoniana and Aspidium Thelypteris gave abundant 
uredinia on Onoclea sensibilis by June 24th, but no infection of 
the others. A third sowing on June 26th on Aspidium The- 
lypteris, Asplenium Filix-femina, Onoclea sensibilis and Phygop- 
teris Dryopteris was followed by abundant uredinia on Onoclea 
sensibilis but no infection of the other plants. A number of 
checks of Onoclea sensibilis remained free from infection. 
These experiments confirm the work of last year and indicate 
clearly that Uredinopsis mirabilis is a distinct species. 1 
Melampsora Medusae Thiim. 
Teliosporic material of this rust collected near Pictou, N. S., 
was sown on young trees of Tsuga canadensis on May 28th. 
Pycnia were present by June 5th, and aecia were first noticed 
appearing on June 8th, both in great abundance. Five trees kept 
as checks showed no infection. Branches of Tsuga canadensis 
bearing cones were placed in water and germinating teliosporic 
material suspended above the cones on June 20th. Pycnia were 
present on the cones on June 27th and were soon abundant, but 
only one matured aecia. Doubtless the failure to mature aecia 
was due to the unhealthy condition of the cones, most of them 
dying before the aecia had time to mature. 
Attempts were made to infect Lari, v laricina (Du Roi) Kooh. 
in the field, but without success. Two sowings of germinating 
1 See Mycoi.. 4: 236. 1913. 
