380 Reed : The mildews of the cereals 



2* Three varieties were used. The results include one test, two plants moculated 



with conidia from Tritiaim compactum, 



2^ Includes one test, two plants inoculated with conidia from Triiicum dicoccum ; 

 one test, three plants inoculated with conidia from T. durum; one test, one plant 

 inoculated with conidia from T, polonicum ; and one test, three plants inoculated with 

 conidia from 1\ Spelta, 



'^Includes one test, two plants inoculated with conidia from Tritii.ttm dicoccufft ; 

 three tests, eleven plants inoculated with conidia from T. dnru»i ; two tests, five plants 

 inoculated with conidia from T, polonictwi ; and two tests, seven plants inoculated with 

 conidia from 7! Spelta, 



^^ Includes three tests, eight plants inoculated with conidia from Hordeton Zeocriton. 



2s Includes one test, three plants inoculated with conidia from Trtticitm compactum ; 

 four tests, eleven plants inoculated with conidia from T. dicoccum; one test, two 

 plants inoculated with conidia from T, durum ; three tests, seven plants inoculated with 

 conidia from T. polonkum ; and two tests, three plants inoculated with conidia from 

 T. Spelt a. 



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To these general statements there are two possible exceptions. 

 Marchal states that the oat mildew will infect Arrhenathemm 

 elatiiis. Salmon, however, obtained a negative result with the oat 

 mildew on this grass. The evidence is not conclusive either way. 

 The other exception is that, according to Salmon, conidia from 

 wheat can infect Hordcum silvaticum. This species, however, is 

 given in the Index Kewensis '21.% Elymiis eiiropaeiis. Furthermore, 

 only young plants of this grass could be infected with the wheat 

 mildew. 



It would seem then that under normal conditions there are 



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well-defined forms oi Erysiphc Grauiinh occurring respectively on 

 the species of each of the four cereals. 



Especially interesting, are the results with the hybrid between 

 rye {Sccale cereale) and wheat {Tritiaim viilgare). Professor Bu- 

 bak, from whom I obtained the seed, informs me that the seed 

 came originally from hybrids obtained by Rimpau in Germany. 



So far as I can determine, a hybrid between rye and wheat has 

 been obtained by three different workers. Wilson,'" in 1875, 

 placed rye pollen on the stigma of the wheat flower and thus 



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secured a number of seeds. These seeds gave rise to plants the 

 appearance of whose culm and head was intermediate between rye 

 and wheat. The awns were midway in length between the short, 

 blunt awns of the wheat, and the long, needle-like awns of the 

 rye. The thickness of the culm and the slight villosity below 

 the head were also rye characters. The hybrids were entirely 



