4 FUNGOID PESTS OF CULTIVATED PLANTS. 



sporules, however, are larger (5-6 x 2 J p) and divided by a transverse 

 septum into two cells. 



Sacc. Syll. x. 5969 ; Grevillea, xv. 1887, p. 108. 



WILD PRIMROSE LEAF- SPOT. 

 Septoria Primula (Buck), PI. IV. fig. 66. 



We have included also this leaf -spot, which was found on the leaves 

 of uncultivated Primroses near Bristol, and, apparently, has not been 

 recognised elsewhere. 



The spots are conspicuous chiefly on the upper surfaces of the leaves, 

 and are somewhat rounded and pallid, with a brown border. The peri- 

 thecia are dot-like, and are scattered over the spots, which are scarcely to 

 be distinguished from the other two forms of leaf-spot. 



The sporules are very different, for in this instance they are long and 

 threadlike (45-50 p long) and apparently nucleate. 



It has never been shown that there is any connection between these 

 three genera of leaf -spot fungi, and it is scarcely probable, since any 

 genetic connection would probably be with fungi of a higher order, and, 

 presumably, of the Sphceriacece. 



Grevillea, xiv. 1885, p. 40 ; Sacc. Syll. x. 6389. 



PRIMROSE -SMUT. 

 Urocystis primulicola (Magn.), PI. IV. fig. 75. 



In some of its features this smut bears slight resemblance to the 

 Violet smut, but it differs in that it attacks the fruit, so that all the seed 

 capsules are filled with smut instead of seeds, and unless eradicated will 

 continue to appear year after year. Its first appearance in this country 

 was recorded in the autumn of 1884 upon Primula far inosa, although it 

 is said to have been seen as far back as 1867. 



The glomerules of spores are roundish or irregular, and are composed 

 of from seven to ten teleutospores, which are normally globose, but 

 become angular by compression, of a dark brown colour, and smooth 

 (9-15 fj). The outer circle of sterile and pale-coloured spores is nearly 

 of the same size and shape. 



Germination takes place after a similar manner to that of the Violet 

 smut. A short thick process or promycelium is thrust out, and this bears 

 another generation of smaller and secondary spores at its extremity, and 

 these again can produce their like. These secondary spores are engaged 

 in the dissemination of the species. 



This is a deep-seated endophyte, not to be dislodged when once it 

 takes possession of a plant. It has been found in Silesia, Saxony, and 

 Italy. 



Sacc. Syll. vii. 1899 ; Gard. Chron. Aug. 30, 1884, fig. 52 ; Plowr. 

 Brit. 7red. 289. 



PRIMROSE CLUSTER-CUPS. 

 JEcidium Primula, DC. 



These, cluster-cups, on the leaves of Primula of various species, might 

 .Jiave been included with the rust, only that the habit is so different as to 



