184 DISEASES OF FIELD & GARDEN CROPS. [CH. 



We believe we have seen instances of the spawn of 

 the ^Ecidium being perennial in the barberry. The 

 mycelium which gives rise to rust and the mycelium 

 from which ^Ecidium arises hardly appear to us to be of 

 the same nature. Attention has lately been redirected to 

 the occasional growth of j&Scidiwn Berberidis, Pers., on gar- 

 den barberries, especially on Mahonia Aquifolium, Lind. 

 It has been suggested that there may be garden barberries 

 in Australia, and that these plants may be infested with 

 the ^Ecidium said to belong to corn mildew. This may 

 possibly be correct, although no evidence has at present 

 been forthcoming in that direction. If garden mahonias 

 are found to bear JEcidium in Australia we imagine the 

 number of diseased garden mahonias on that large Conti- 

 nent will be in about the same proportion to the vast corn- 

 fields there found, as the borage dEcidium is to the corn- 

 fields of Britain, or as the fungus of Poo, annua, L., is to 

 the dEcidium of coltsfoot and butter-bur. 



Mr. Charles B. Plowright was kind enough to send us 

 a good collection of Mahonia berries invaded by jtEcidium, 

 as illustrated in Fig. 87. Occasionally the disease ap- 

 peared upon the leaves and stalks, and from our examin- 

 ation of them we were inclined to think the mycelium of 

 the fungus traversed the entire plant, and especially the 

 berry with its seed. We successively planted a number 

 of seeds at overlapping intervals through last summer, 

 but not one germinated. This suggested to us that the 

 plasma of the fungus had reached the embryos of the seeds 

 and killed them. On inquiring of Mr. B. S. Williams, 

 the well-known nurseryman of Upper Holloway, he 

 informed us that Mahonia seeds germinate freely when 

 the seed has been matured, is good, and properly planted. 

 Mr. Williams said Mahonia seeds took from two to three 

 months to germinate, and he kindly undertook to test 

 twelve ripe berries for us, each berry showing the 

 ^-Ecidium disease. The seeds were sown carefully in two 

 pots, and after the proper time had elapsed no single seed 



