236 
]\Iycologia 
infection of Pcridermium balsamenm. The distribution of the 
aecia on the trees indicated that infection had come from the 
rusted ferns of the previous season. These observations were 
made in a number of places. 
Uredinopsis Atkinsonii Magn. 
Aeciospores of P eridcrmium balsameum from Abies balsamea 
which seemed from field evidence to be connected with this rust 
on Aspidiiim Thelyptcris Sw. were sown on a pot of these ferns 
on July I, but without infection. Another sowing on July 3 of 
similar material gave uredinia which appeared on July 10, but not 
in great abundance. Three pots of Aspidiiim Thelypteris were 
kept as checks and remained free from infection. There was 
some field evidence of the connection of these forms but it was 
not very pronounced. 
Uredinopsis Phegopteridis Arthur 
Teliosporic material of this rust on Phegopteris Dryopteris 
(L.) Fee was suspended in the usual way above Abies balsamea 
on May 27. Pycnia appeared on June 12 followed by aecia. In- 
fection was not marked, only about twenty of the young leaves 
bearing aecia. Observations in the field also indicated the con- 
nection of these forms. 
Uredinopsis mir.\bilis i\Iagn. 
Teliosporic material of this rust on Onoclea sensibilis L. was 
suspended above Abies balsamea (L) ]\Iill. on Alay 13. Pycnia 
and aecia followed, the latter being first noticed on June 6, 
about a dozen leaves showing aecia. 
Aeciospores {Peridermium balsameum) from Abies balsamea 
were sown on two pots of Onoclea sensibilis on June 28. 
Abundant uredinia followed, being first noticed on July 5, the 
urediniospores were oozing out by July 8. 
Another sowing of aeciospores was made on Onoclea sensibilis, 
Onoclea Strnthiopteris and Aspidiiim Thelypteris on July i. 
Abundant infection of the pot of Onoclea sensibilis followed, the 
uredinia being present on July 8. None of the other ferns 
showed infection. 
