202 DISEASES OF FIELD & GARDEN CROPS. [CH. 



the resting-spores attack barberry bushes, or whether they 

 do not, is of no great importance, for there are generally 

 no barberry bushes to attack. The mildewed straw should, 

 as far as practicable, be destroyed, and the hedges kept 

 clear of rusted and mildewed grasses. 



In taking the position here advanced in regard to the 

 fungi of corn mildew and barberry blight, it must not be 

 assumed that we tinder-estimate or disrespect the valuable 

 published opinions of other observers. Those published 

 opinions are, some of them, counter to ours, and we know 

 the risk we run in appearing to question them. Still, 

 the conclusions here given have been arrived at after 

 many years' study, with living examples before us, and 

 if we are not right in our opinion, we think we have 

 advanced a sufficient number of facts to show that new 

 and better evidence is much needed before the connection 

 of corn mildew and the blight of barberries can be gener- 

 ally accepted as proved. Physiology and pathology have 

 taught us much, but there is infinitely more to learn. 



No account of the supposed connection of corn mildew 

 with barberry blight would be complete without a notice of 

 the essay, by Professor A. S. Oersted, published in Copen- 

 hagen, in the Botanische Zeitung, in 1865. This essay is 

 intended to show that a common fungus of the Savin, 

 named Podisoma Juniperi-Sabince, Fr., is one condition of 

 an equally common fungus of pear leaves named Rcestelia 

 cancellata, Reb. The Podisoma is a close ally of Puccinia 

 or mildew, and the Rcestelia of sEcidium or blight. Pro- 

 fessor Oersted says that he had learned that gardeners were 

 of opinion that the pear fungus was never seen except 

 after the appearance of the fungus on Savin. In contrast 

 with this statement, if we turn to the Mycologia Scotica we 

 find that the fungus of Savin is recorded from Scotland, 

 but that the supposed secondary state belonging to pear 

 leaves is not a Scottish fungus. Scotland is famous for 

 its excellent gardeners, and it appears hardly possible, 

 therefore, that any gardener can have seen in Scotland 



