CARPOSPOREJE. 
335 
which produces the swelling of the leaf constituting the first stage which we considered, 
a mycelium which bears spermogonia and secidium-fruits. 
The genus Roestelia possesses no uredospores. Its secidium-fruits which make their 
appearance in July and August upon the leaves, petioles, and fruits of the Pomacese 
(Pjrus, Cydonia, Sorbus) resemble long-necked flasks and may become as much as eight 
millimetres long ; they open either at their apices or laterally by means of slits. The 
chains of spores present a peculiarity which occurs also in other instances, that between 
any two spores there lies a sterile cell which subsequently decays. The teleutospore- 
fruits belonging to Roestelia (formerly known as Gymnosporangium) appear upon species 
of Juniperus in the spring as spherical, conical, clavate, tongue-shaped, or palmate gela- 
tinous masses of a yellow or brown colour. They consist of closely-placed basidia 
arising from the mycelium which extends beneath the epidermis of the leaves and in 
the cortex of the branches, and bearing the teleutospores. The teleutospores resemble 
those of JEcidium Berberidis, and like them produce promycelia on germination, the 
sporidia of which reproduce Roestelia with aecidium-fruits upon the leaves of Pomaceag. 
Under the name of Hypodermiese De Bary unites the Uredineas with the Ustila- 
gineae, which, however, do not seem to be very closely related to them. The 
UstilagmesB ^ (Smuts) are parasitic in the tissues of Phanerogams, especially of Grasses, 
in which their mycelium ramifies without at first effecting any injury. It is only when 
the fructification, consisting of spherical dark-coloured conidia, is formed that the 
vegetable organ in which it occurs becomes deformed : this usually swells up into 
a vesicle, the whole of the internal tissue being absorbed and replaced by a black 
powder, the conidia of the Fungus. Maize seeds are in this way converted by the 
Ustilago Maidis into vesicles of the size of a nut, which, on bursting, liberate the 
powdery conidia; Oats attacked by the smut are entirely filled with the conidia of 
Tilletia caries. The germinating conidia produce a small promycelium which bears 
sporidia : the hyphae developed from the sporidia penetrate into the sprouting grain 
and the mycelium continues to grow until it produces conidia in the ears. 
C. The Basidiomycetes 
Although this division includes the largest and most beautiful of the Fungi, yet 
it is just here that our knowledge of their life-history is most imperfect. All that 
is certainly known is that the basidiospores developed upon the large fructifications 
consisting of masses of hyphae, germinate, forming mycelia, and that at a later 
period these mycelia bear fructifications. A development of sexual organs, by 
means of which the formation of the fruit could take place, has not as yet been 
observed upon the mycelium ; still, a consideration of our knowledge with regard to 
the Ascomycetes, more especially the Discomycetes, makes it at least probable that 
the spore-producing fructification is to be regarded as a true fruit which owes its 
origin to the as yet undiscovered sexual organs existing upon the mycelium^. 
However this may be, the whole process of development naturally divides itself in 
^ [Tulasne, Memoires sur les Ustilaginees ; Ann. Sei. Nat., ser, 3, VII, ser. 4, II. — De Bary, 
Unters, ueb. die Brandpilze, Berlin 1853. — Fischer von Waldheim, Aperfu systematique des Ustila- 
ginees, Paris 1877. — De Bary, Protomyces microsporus und seine Verwandten, Bot. Zeitg. 1874.] 
^ See De Bary. Morphol. u. Physiol, der Pilze, Flechten, und Myxomyceten, Leipzig 1866. 
^ [From the researches of Brefeld (Basidiomycetes, 1877) it appears that these plants have no 
sexual reproduction. Their large fructifications are comparable to the asexual conidia-bearing 
fructifications of the Ascomycetes. The so-called 'basidiospores' are, like the ' uiedospores ' and 
* teleutospores ' of the /Fcidiomycctes, merely conidia.] 
