38 Set c hell. — An Examination of the Species 
Doassansia Niesslii, De Toni. 
This species inhabits the leaves and peduncles of Butomus 
umbellatus , on which it may be detected by the very pale 
yellow, rather elliptical spots, dotted with the dark-brown 
sori. The only accessible specimens were those distributed 
by Sydow (Myc. March., No. 220 6), from the Botanic Gardens 
at Berlin. 
Careful sections show that the sori are situated in the 
cortical layers just beneath the epidermis. Each sorus lies in 
the chamber immediately under a large stoma. Thin sections 
show at once that this species is not a Doassansia , at least as 
founded by Cornu. The sorus is a rather irregularly ellip- 
soidal body, with its long axis parallel to the long axis of the 
leaf or peduncle which it inhabits. The cross-section is nearly 
circular, and about 50 /x in diameter. In longitudinal section 
it is narrowly elliptical, being about 160/x long and 50 /x across. 
The spores are closely packed together with very few inter- 
spaces, and the exospore, which is moderately thickened, is of 
a light brown colour. The spores have highly refractive light- 
coloured contents, with one or two rather large oil-drops in 
each. They are from 6 /x to 8 /x in diameter. The outer spores 
have darker coloured exospores than the inner ones. There is 
no layer of cortical cells at all. Abundant hyphae are found 
in the immediate vicinity of the sorus, and occasionally a few 
strands form a sort of partial covering for the sorus, but this 
is not as complete as in the two following species. 
The spores seem to germinate in the sorus at maturity as 
they do in D. decipiens. The promycelia are distinct, and the 
sporidia long and slender, but I could not determine from the 
dried specimens either how they were borne or how they 
behaved. 
Season. August and September. 
Distribution. Austria , Niessl \ Germany, Schroeter ; Sydow! 
Literature. 
Protomyces pundiformis , Niessl, Beitr. z. Kennt. d. Pilze, p. 16. 
[Verhandl. d. Naturf. Ver. i. Briinn, Bd. X.] 1872. 
