spring have frequently seen yellow spots upon their leaves 

 (PI. L, Fig. i), wheje threads of mycelium can be seen thickly 

 running throughrtfeeiKpferenchyma. In these spots there 

 kinds of fructification. The one consists of numerc 

 like bodies detached from hyphae, or branches, 

 mycelium formed in urn or flask-shaped receptacle^ 

 upper side of\the leaf (PI. I;.; Figs, i and 2). It hat; 

 been discovered what functions these spermogonia^ perform.* 

 The other fructification occurs on the underside of th^barberry 

 leaf, appearing, firstyas groups of tiny dots (PL I., Figs. 3 and 4). 

 These are surrounded with mycelial threads, and when ripe 

 they burst through the epidermis, or skin, of the leaf, forming 

 cups or bell-shaped cavities (PI. L, Fig. 5, A. & B). In the bot- 

 tom of the ^Ecidium cup there is a hymenium or collection of 

 " mother spore cells," from whose hyphae spores are being con- 

 tinually given off. They are not quite round, f and are 

 inconceivably numerous, so that thousands may be dissemi- 

 nated far and wide by the wind from one spot, or vEcidium 

 cluster. Mr. Marshall Ward, writing of another species of the 

 Uredineas,- the Hemileia vastatrix, the pest of Ceylon coffee 

 planters, estimated that upon one " disease spot upon a leaf of 

 a coffee plant there were 150,000 spores present." There 

 were 127 " disease " spots upon one pair of leaves, so that the 

 number of spores upon one plant might be beyond calculation. t 



In Plate L, at Figure 5, is shown a transverse section through 

 a barberry leaf infected with JEcidium berberidis, displaying the 

 ^Ecidia in two forms at the lower part, (A. & B.) and the 

 spermogonia on the upper part, (E. & D. D.), with intercellular 

 spaces invaded, (C.) 



Mr. Carruthers, in a concise report upon the wheat mildew, says, 

 "the quantity of spores produced on a barberry leaf is enormous." 



These spores, .known as ^Ecidiospores, germinate readily 

 upon the leaves of the wheat and oat plant, and many grasses, 

 as enumerated by Mr. Plowright.il De Bary first germinated 

 these spores upon wheat plants, and his experiment has been 

 repeated by others. Mr. Marshall Ward observes, " These 

 yEcidiospores will germinate readily in water on the leaves of 

 wheat, and their germ tubes enter the stomata, and develop a 

 mycelium whiclj gives rise to the uredospores, and eventually 

 to the teleutospores of Puccinia graminis"^ 



Mr. Worthington Smith says, " these spermogonia are supposed to be 

 little grains belonging to a male organism roughly answering to the pollen 

 of flowering plants." Diseases of Field and Garden Crops, by Worthington 

 G-. Smith. 



f Sachs says, " Originally of a polyhedral form in consequence of pressure 

 from opposite sides, they afterwards become rounded." A Text-book of 

 Butany, by Julius Sachs. 



J Report on the Coffee Disease, by H. Marshall Ward, Esq., 1881. 



The Wheat Mildew, by W. Carruthers, F.R.S., Journal of the Royal 

 Agricultural Society of England, vol. xviii., 2nd Series. 



|| The Gardeners' Chronicle, August 1882. 



^f Illustrations of the Structures and Life History of Puccinia Graminis, the 

 Fungus causing the Rust of Wheat, by Marshall Ward, M.A., F.R.S., F.L.S. 

 Annals of Botany, vol. ii., 1888-9. 



