of the Genus Doassansia , Cornu. 1 1 
The mycelium is abundant and closely resembles that of 
D. alismatis in all respects. 
The sori are nearly globular, rather dark brown bodies from 
100 fji to 1 25 11 in diameter. The spores are rather loosely 
compacted together, nearly spherical, and from 8 to 10 1± 
across. The outer coat is moderately thick and light-coloured, 
and the granular contents usually possess one large globule 
of oil. The cortical cells are rather short and broad with 
rather thin, light-brown walls. They closely cover the sorus, 
but are rather irregular (Fig. 71). 
The germination has been given in some detail by Fisch 
( 1 . c., pp. 408 et seq.). The promycelium, according to him, 
has a markedly conical tip ; the sporidia are inserted at un- 
equal distances on this tip ; they produce secondary sporidia 
without conjugating ; and these secondary sporidia conjugate 
in rare instances. The characters of the shape of the tip of 
the promycelium and the unequal insertion of the sporidia are 
not found in any other species of Doassansia of which the 
germination has been obtained, and are in striking contrast 
with those of D. alismatis , as may be seen above. Fisch also 
says ( 1 . c.) that D. sagittariae will germinate only in spring 
and early summer ; while D. alismatis , as shown above, will 
germinate readily at almost any time of the year. 
D. sagittariae differs from D. alismatis by the uniformly 
smaller size of the sori, by the arrangement and shape of the 
cortical cells, and by the characters of the promycelium and 
sporidia. It is near D. alismatis , but yet, as it seems to me, 
perfectly distinct from it. From D. hottoniae it is distin- 
guished by its habit, and by its smaller and more globular sori. 
Season. From May until September. 
Distribution. D. sagittariae is fully as widely distributed 
as was the preceding species. In Europe it has been found 
in Italy, Bizzozero ! France, Briar d ! Germany, Fuckel ! 
Magnus ! Whiter ! Hening ! Schroeter ; England, Vize ! 
Belgium, Westendorp ! in South America, in the Argentine 
Republic, Spegazzini ; in North America, in Missouri, De- 
