142 
In the genus Tilletia the signed of such idis are has 
not been demonstrated, but the species enumerated the 
following pages are founded on füctbholdgici “pape 
nation of a large amount of material has led to the con- 
clusion that the host-plant is absolutely worthless as a factor in 
the discrimination of morphologically defined species. For this 
reason the es as here understood, do not a o those 
of many previous workers, where the host was an important, and 
. not tifreqtiently the only feature relied uis for E Aiari 
between ee distinct but allied 
th regard to geographical distribution, the genus is very 
widely distr. whereas the species are restricted in their 
range, each being confine d to a portion of one Continent, with the 
exception of those species that are parasitic on cultivated 
cereals, the explanation of which is obvious. Of these Tilletia 
Caries occurs in Europe, Africa, Australia, United States, South 
America; T. levis in Europe, Australia, United States ; 7. Hordei 
in Europe, Asia, Africa. 
The following table shows the distribution of the species :— 
Europe, 13 species.—/evis, de Baryana, ice Lolii, 
controversa, separata, Caries, Rauwenho Hordei, 
endoph ylla, Seslerie, Berk eleyi, Sphagni, (Fise heri ?). 
ia, 2 species.—controversa, Hordei, ( Vulpie ?). 
Africa, 2 species. —Verrucosa, ; Cries, Hordei, 
Mauritius, 1 species.—4 yv: 
Australia, 4 species. levis, aed. epiphylla, Caries. 
United States, 9 speci —levis, rotundata, miata, rugis- 
pora, cerebri ina, p and Caries, Elymi, fusca. 
Antilles, 1 species. —magnus 
South America, 3 species. d Be ‘a, Caries, zonata. 
TILLETIA, Tulasne in Ann. Sci. Nat, ser. 3, vol. vii, p. 112 
(1847) ; Sace., Syll. vii. (1888), p. 481. 
Endophytie Mee parasites. Spore-mass pulyerulent, black 
or blackish-olive at maturity, often foetid, especially when 
moistened. Siporés 8 free, produced singly at the tips of somewhat 
gelatinous, swollen, fertile hyphe, at first covered by the epidermis 
of the host, forming a blackish powdery mass at maturity. On 
germination, the spore gives origin toa promycelium, which bears 
a terminal whorl of slender, elongated secondary-spores at its apex. 
Secondary-spores usually conjugating in pairs, and on germination 
producing slender, elongated conidia.— Ustilago, Link, in Berl. 
Mag. der Gesellsch. der Nat. Freunde, iii. (1809) ; Lév., in Ann. 
Sci. Nat., sér. 2, xi. (1839), 116. 
Tulasne separated the species included under Pilletia, from the 
heterogeneous assemblage of species er included under 
Ustilago, Uredo, Erysibe, &c., of old authors, taking as his 
rincipal generic character, the peculiar ‘ines of germination and 
production of secondary-spores as observed in Tilletia Caries 
(7. Tritiei, Winter). 
'The principal distinctive features of Tilletia, as defined by 
systematist are poto adem free (not rn in groups), E ins 
