REED: SPECIALIZATION OF PARASITIC FUNGI 315 
1. Uromyces Pastinacae-scirpi Kleb.; aecidial stage on Pastinaca 
sativa. 
2. Uromyces Berulae-scirpi Kleb.; aecidial stage on Berula angusti- 
folia. 
Dietel (28) was able to infect with teleutospores from a single host 
Sium latifolium and Hippurus vulgaris. 
Gymnosporangium tremelloides Hartig. There is but little indi- 
cation in the literature of the existence of specialized races in Gymno- 
sporangium. Most of the species of this genus are quite restricted in 
host range, often occurring on only a few species of a single genus of 
host. Klebahn (89) gives some evidence for a host specialization of 
Gymnosporangium tremelloides, the teleutospores of which are produced 
on Juniperus communis. On the basis of cultural tests he suggests the 
following: 
1. Gymnosporangium Ariae-tremelloides WKleb. Aecidial stage on 
Sorbus aria and S. torminalts. 
2. Gymnosporangium Mali-tremelloides Kleb. Aecidial stage on Pyrus 
malus. 
Ochrospora Ariae (Fuckel.) Syd. Fischer (45) stated that he was 
unable to infect Aruncus silvestris with uredospores of Ochrospora ariae 
from Sorbus aucuparia. Tranzschel (152, 153), Fischer (45) and 
Klebahn (89) showed that Sorbus aria, S. scandica and Pyrus malus 
were all hosts of the same race, but Aruncus silvestris could not be 
infected with spores from the same source. Later, however, Fischer 
(48) was able to infect Sorbus aucuparia and Aruncus silvestris with 
the same aecidiosporic material from Anemone nemorosa. 
Pucciniastrum Abieti-Chamaenerii Kleb. and P. Epilobii (Pers.) 
Otth. These two rusts, according to Klebahn (83, 87), are dis- 
tinguished almost solely on the basis of their life cycle. The former 
is heteroecious with its aecidial stage on Abies balsamea and A. pectinata 
and its uredo and teleuto stages on Epilobium angustifolium, E. 
Dodonacum and E. latifolium. The latter has its uredo and teleuto 
stages on a number of other species of Epilobium and its aecidial host 
is as yet not known. 
Phragmidium disciflorum (Tode.) James. Bandi (15) suggests 
that a host specialization occurs in this rust. He reports one race on 
Rosa cinnamomea, R. pimpinellifolia and R. rubrifolia and a second 
race on R. canina and R. centifolia. 
Coleosporium Campanulae (Pers.) Lév. This rust has its aecidial 
stage on Pinus montana, P. rigida and P. sylvestris, and its uredo and 
teleuto stages on a considerable number of different species and general 
of the Campanulaceae. Wagner (170) and Klebahn (87, 91) have 
made extensive studies with reference to the specialization of the rust 
on different hosts. Klebahn makes the following races: 
