POLYMORPHISM. 197 
from the foregoing, finds illustration in the spheriaceous genus 
Melanconis, of Tulasne, in which the free spores are still called 
conidia, though in most instances produced in a sort of spurious 
conceptaculum, or borne on short threads from a kind of 
cushion-shaped stroma. In the Melanconis stilbostoma,* there 
are three forms, one of slender minute bodies, oozing out in the 
form of yellow tendrils, which may be spermatia, formerly called 
Nemaspora crocea. Then there are the oval brown or olive brown 
conidia, which are at first covered, then oozing out in a black 
pasty mass, formerly Melanconium bicolor, and finally the sporidia 
in asci of Spheria stilbostoma, Frics. In Melanconis Berkeleii, 
Tul., the conidia are quadrilocular, previously known as Séilbo- 
spora macrosperma, B. and Br. In.a closely-allied species from 
North America, Ielanconis bicornis, Cooke, the appendiculate 
sporidia are similar, and the conidia would also appear to partake 
of the character of Stilbospora. We may remark here that we 
have seen a brown mould, probably an undescribed species of 
Dematiet, growing in definite patchcs around the openings in 
birch bark caused by the erumpent ostiola of the perithecia of 
Melanconis stilbostoma, from the United States. 
In Melanconis lanciformis, Tul., there are, it would appear, 
four forms of fruit. One of these consists of conidia, charac- 
terized by Corda as Coryneum disciferme.~ Stylospores, which 
are also figured by Corda under the name of Coniothecium betu- 
dinum ; pycnidia,§ first discovered by Berkeley and Broome, and 
named by them Hendersonia polycystis ; || and the ascophorous 
fruits which constituted the Spheria lanciformis of Fries. Mr. 
Currey indicated Hendersonia polycystis, B. and Br., as a form 
of fruit of this species in a communication to the Royal Society 
in 1857.4 He says this plant grows upon birch, and is in per- 
fection in very moist weather, when it may be recognized by the 
* Cooke, ** Handbook,” ii, p. 878; Tualasne, ‘‘Carpologia,” ii, p. 120, 
plate 14. i 
+ Tulasne, ‘‘Selesta Fung. Carp.,” ii. plate 16, 
t+ Corda, ‘* Icones Fungorum,”’ vol. iii. tig. 91. 
§ Corda, ‘‘Icones,” vol. i. fig. 25. 
|| Berk. and Br. ‘‘ Ann. Nat. Hist.” No. 415. 
{ Currey, in ‘‘ Philosoph. Trans. Roy. Soc.” (1857), pl. 25. 
7 
