REED: SPECIALIZATION OF PARASITIC FUNGI 359 



Stakman's (143) results with the cereal rusts, in general, confirm 

 those of Freeman and Johnson. He found that uredospores from 

 barley infected rye, barley and wheat, but not oats; uredospores from 

 oats infected wheat, rye and oats, but not barley; uredospores from 

 rye infected rye, but not wheat nor barley; uredospores from wheat 

 infected barley, rye and wheat, but not oats. Uredospores from 

 Agropyron repens gave the following results: on wheat, on oats, on 

 barley and on rye. 



Stakman (144) briefly mentions some other results with this rust. 

 He states that uredospores from Agropyron repens, A. tenerum, A. 

 caninum, A . smithii and Hordeum jubatiim readily infect barley and 

 rye, very slightly wheat and practically fail to infect oats. Uredo- 

 spores from DactyUs glomerata and Poa nemoralis infect oats, but not 

 the other cereals. Practically no success was attained in trying to 

 infect any of the cereals with uredospores from Agrostis alba, A. 

 stolonijera, Anthoxanthum odoratum, Calamagrostis canadensis, Poa 

 pratensis and P. compressa. 



Bolley and Pritchard (20) state that uredospores from barley 

 {Hordeum jubatiim) and Avena fatua were able to infect wheat and 

 uredospores from wheat produced infection on barley and Hordeum 

 jubatiim. 



Pritchard (no), in North Dakota, suggests that distinct races 

 occur on wheat and barley, although he gives no experimental evi- 

 dence. Another race occurs on rye, oats, Avena fatua, Agropyron 

 repens, A. tenerum and Hordeum jubatum, as indicated by inoculations 

 with uredospores from the gramineous hosts and aecidiospores from 

 the barberry. 



Gassner (58) has reported brief results on this rust in South America. 

 He was able to infect wheat with uredospores taken from barley, oats, 

 rye, Lolium temidentum and Dactylis glomerata. Barley was also 

 infected by uredospores from wheat. 



As noted before, the infecting capacity of aecidiospores from bar- 

 berry has been tested, as well as that of the uredospores from various 

 gramineous hosts. Eriksson (41) has infected the barberry with 

 teleutospores from more than fifty different grasses. In some cases 

 the aecidiospores thus experimentally produced were .used to inoculate 

 various grasses. In general, the aecidiospores from the barberry are 

 restricted in their ability to infect grasses in the same way as uredo- 

 spores from the grasses which were used as a source for the teleuto- 

 spores for inoculating the barberry. It should be noted, however, 

 • that aecidiospores from the barberry, produced by inoculation with 

 teleutospores from Bromus madritensis, Briza maxima, Festiica myurus 

 and Phalaris canariensis , recorded as hosts for the specialized race 



