49 2 Freeman.- — Experiments on the Brown 
it is very doubtful if these were due to the infecting Fungus ; 
no pustules were produced. The results with B. arvensis are 
at variance with those of Marshall Ward, who has found 
a successful infection of about 37 per cent. It is possible 
that at least some of the negative results of series A are due 
to weather conditions. 
Series B contains about eleven species. In B. adoensis , 
B. arduennensis , B. mollis , B. squarrosus , and B. squarrosus 
var. villosus , the percentage of successful infections is notably 
high. B. arduennensis , although the number of plants used 
is small, seems to be decisive in its results. B. grossus , B. 
midtiflorus and B. patidus are also decisive but show more 
resistance to B. mollis spores, about 50 per cent, being 
successful. B. commutatus and ‘ B. inermis (arvensis)! which 
latter is probably identical with No. 34, shows still less liability 
to infection. B. macrostachys requires more study, the single 
successful infection being insufficient for generalization. 
Number 27 (and 34?) are Canadian forms and are probably 
B. arvensis , which, although my experiments give negative 
results, are according to those of Marshall Ward occasionally 
infected with B. mollis spores. In series D, B. Krausei , 
B. pendulinus and possibly B. vestitus , are more susceptible to 
mollis infection than to sterilis. 
Series C contains only B. sterilis . In the following series 
B. Gussoni has a much higher percentage of sterilis infections 
than of mollis. 
Series D contains five species. B. Gussoni infects very 
readily (over 50 per cent.) with sterilis spores and over 10 per 
cent, with mollis. On the other hand, B. vestitus and B. 
pendulinus show greater susceptibility to mollis spore infection 
than to sterilis , but good percentages with both. In B. molli- 
formis the percentages are too low and the differences insuffi- 
cient for generalization, while B. Krausei infects with both 
species with remarkable ease. In the latter case infection with 
mollis spores is effected as easily if not more so than upon mollis 
itself, and the pustules are remarkable for size and vigour. With 
sterilis spores almost 30 per cent, were successfully infected. 
