xxv.] CORN MILDEW AND BARBERRY BLIGHT. 203 



the pear fungus following the one on Savin. Savin, like 

 the barberry, is absent and under a general ban in many 

 country places, owing to the improper use to which the 

 fetid volatile oil from the leaves has often been put as 

 an emmenagogue ; but pear leaves with the Rcestelia are 

 everywhere common. The Rev. M. J. Berkeley has 

 recorded in Hooker's British Flora, vol. v. part ii. p. 5, 

 that when young pear trees are planted near old ones 

 suffering under the Rcestelia, the young trees have been 

 observed to become much injured by the fungus ; and 

 Mr. Knight sowed pear seeds in soil infested with 

 Rwstelia, and the very youngest leaves of the seedlings 

 showed the disease. 



Professor A. S. Oersted carried out the usual successful 

 infecting experiment, but in regard to it he very properly 

 remarked : "It may very easily happen that the above 

 experiment may be repeated many times without success, 

 for those who are occupied in this kind of work know that 

 a certain amount of good fortune is necessary for success." 



The correctness of Professor Oersted's experiments and 

 views were confirmed by Professor De Bary of Strasbourg 

 in the same year, Bot. Zeit., p. 222, 1865, and this confir- 

 mation tended greatly towards the general acceptance of 

 Professor Oersted's view. Two other species of European 

 Rcestelice allied to R. cancellata, Reb., were also connected 

 with two allied European species of Podisoma, related to 

 P. Juniperi-Sabinw, Fr. 



In the Anniversary Memoirs of the Boston Society of 

 Natural History, Professor W. G. Farlow of Harvard Uni- 

 versity, a gentleman who studied with Professor De Bary, 

 and therefore had good opportunities of seeing original 

 experiments carried out with germinating fungus spores, 

 has published a paper termed the Gymnosporangia, or Cedar 

 Apples of the United States : Boston, 1880. In this paper 

 Professor W. G. Farlow reviews the whole evidence for 

 the connection of Roestelia with Podisoma (or, as he terms 

 it, Gymnosporangium) in the light of the large number of 



