LICHENS AND FUNGI OF OTACO, NEW ZEALAND. 433 



species, it might be regarded as a distinct species of which I know of no description. 

 It is not the JE. australe of Berkeley, which is a Rcestelia, I think." 



So far as my data enable me to judge, it appears to me to be the same Fungus, 

 which is parasitic on the three Phsenogams above mentioned; and it seems doubt- 

 ful, so little do they vary in their characters, whether the three forms deserve 

 separate consideration or classification as varieties. The Peridia occur— most 

 generally on the leaves of the plants on which they grow — as a series of minute 

 cups or saucers sunk in the tissues of the matrix ; pale buff-coloured in the 

 centre, with a darker projecting margin. In shape and colour, these have consi- 

 derable resemblance to the urceolate apothecia of the old Lichen-genus Gyalecta 

 (fig. 64 b). To the naked eye they generally appear to be a series of minute, 

 round, buff-coloured spots, sometimes from their abundance giving the leaf on 

 which they grow a yellowish or reddish tinge, with a dry, withered, or puckered 

 character (fig. 69 b). For their proper examination, however, they require the 

 aid of the microscope and lens ; and the examination should be made on fresh or 

 living specimens— for this is one of the many genera of Fungi, whose species can 

 only in this way be accurately determined or fully described. In so far as my 

 specimens were all examined in the dried state, in the Herbarium, my data for 

 determination and description are confessedly imperfect* It remains, therefore, 

 for local Botanists to settle such questions in the natural history of the genus 

 Mcidiurn and its species (as developed in New Zealand) as the following :— 



1. Whether the genus is autonomous, and not a mere form or condition of 

 other Uredineee, as Oersted and De Bary suggest ? 



2. Whether, assuming that it is a good genus, it contains so many good 

 species as is at present supposed ? This is a subject regarding which the most 

 eminent Fungologists are somewhat at issue. On the one hand, Mr Currey writes 

 me — " I have no faith in the species of JEcidia : I think that in all probability they 

 are reducible to two or three, if not to one, species." On the other hand, Mr Cooke, 

 though admitting, doubtless, their great variability and complexity, describes no 

 less than thirty-one British species alone. 



3. Whether JR. Otagense differs so essentially from species already described 

 as to deserve a permanent place as a separate species ? It differs from the only 

 two species recorded in the " Flora Novse Zelandise," JE. Ranunculacearum, DC, and 

 JE. monocystis, Berk, (which is apparently confined to New Zealand). Nor does it 

 appear to agree in all particulars with any of the thirty-one British JEcidia. The 



* In all three cases of the parasite on Clematis, Epilobium, and Microseris, the Fungus was 

 determined to be a true Mcidiurn (as the genus is at present established), by the presence of its 

 characteristic spores. " jEcidia," says Mr Curkey, in reference to some difficulties that occurred to 



uie in my microscopical examination, " never bear thecce In the early state of JEcidium, 



the perithecia produce minute spermatid ; but neither in that state, nor in the more advanced con- 

 dition, have asci (thecse) ever been observed The spores are always produced in chains ; and 



when they fall apart, after the opening of the cups, they produce the yellow dust (or white) with which 

 the cups are filled." — Letter, March 22, 1865. 



