432 DR LAUDER LINDSAY ON THE 



inwards or upwards.* Its texture becomes thickened and sub-coriaceous ; and 

 this change is most evident, when leaves affected by the parasite are compared 

 with those unaffected ; which, in the latter case, are thin, sub-membranous and 

 altogether of greener colour, with a healthier, fresher, younger appearance, and 

 more flaccid consistence. The mal- conditions, or deformity here produced by the 

 parasite, are, however, much less marked than in the case of Clematis or of 

 Microseris. 



The Peridia on the specimens examined by me were generally regularly round 

 and deeply urceolate (fig. 70) ; the sunk disk was always of a lighter colour than 

 the raised margin, both being, however, pale buff or brownish. Sometimes both 

 disk and margin assumed the same colour as the faded-looking leaf — a russet brown. 



" Possibly," says Mr Cooke, " your JEcidium on Ejrilobium is JE. Epilobii, 

 DC, which has some of the habits of the present species.' 1 



3. Parasitic on the leaves of Microseris Forstei'i, Hook. fil. ; growing in 

 marshy places, Abbott's Creek, Greenisland ; October to December ; in flower. 



Generally the Peridia occur as oblong or ellipsoid papillae or tubercles, un- 

 marked or unpierced by an ostiole in the young state, but exhibiting various 

 forms of urceolse— for the most part with irregular margins— in the old state 

 (figs. 71, 72). Essentially they resemble in appearance and structure the Peridia 

 which occur on Clematis. They also resemble, however, more than do the Peridia 

 on Clematis or Epilobium, the wart-like apothecia of Pertusaria, including both 

 the normal and variolarioid conditions of the latter. 



Mr Cooke makes the following interesting remarks regarding this form of the 

 parasite : — " I should say that your specimen on Microseris is closely allied to 

 ^E. Tragoponis, Pers., and that it certainly is not the very common and variable 

 jE. Compositarum, Mart. All the marginal teeth are gone, and most of the spores. 

 If it could be determined whether the Peridia were seated on any definite coloured 

 spot (l think they were not), and what the colour of the spores in the fresh state, 

 and whether that colour was fixed or mutable, we could say definitely whether 

 it really is jE. Tragoponis. My own impression is that it would prove to be an 

 undescribed species; but there is not sufficient material to state for certain, or to 

 describe it if new. The colour of the spores, when fresh, is of specific value— as 



at present acknowledged — whether rightly or wrongly You will 



observe that .... the Peridia are scattered, and not collected in definite 

 clusters. These are not so numerous or close as in JE. Tragoponis, as you will 

 see by reference to Plate I. fig. 1 of my ' Microscopic Fungi.' .... In 

 ^. Tragoponis the spores are at first yellow, then blackish. If, from a better 

 specimen, you can determine that the spores are permanently yellow in your 



* Similar thickening and involution of the edges of the leaves on which they grow are some- 

 times caused hy British species, e.g., JE. Asperiifolii, Pers., and j3S. Euphorbice, Pers. (Cooke, 

 " Introd.," p. 191-2.) 



