628 THE SMALLER FUNGI. 
spores of Uredo, which are produced in immense quantities, 
- and soon cover the pustules with a deep brown dust. Later, 
4 
the formation of the stylospores is arrested, and the true 
germinating spores appear in the same pustules. 
The stylospores of Uredo are borne singly at the top of 
short filaments. On arriving at maturity they detach them- 
selves. They are of a globular form, with a reddish brown 
epispore (covering), provided with little pointed promi- 
nences, and three pores at equal distances. After maturity 
they germinate in precisely the same manner as the stylo- 
spores of the cluster-cups. They enter only through the 
stomata of the epidermis (skin of the leaf). The pulvinules 
(clusters of powdery spores) are identical with those which 
the stylospores of Æcidium originate, and they also produce 
true spores at the end of their vegetation. No other fruit 
arises from them. These organs, therefore, always repro- 
duce the same form to which they owe their origin. 
- The result of these investigations shows that the Bean 
Rust (Uromyces appendiculata), besides spermogones, pos- 
sess four sorts of reproductive organs, which all ‘serve to 
propagate the species, but that one alone of them produces 
it in'a form always identical, while the others present well 
marked alternations of generations. Hence it is concluded ° 
that there are, first, Spores, which produce the germinating 
promycelium;* second, Sporidia,—these give place toa 
mycelium, which bears afterwards ; third, Æcidium (a con- 
dition which exhibits),—particular organs which engender 
stylospores, and which produce, fourth, the Uredo, or 4 
second form of the stylospores and later spores (No. 1), 
which are always associated with Uredo in the same pustule. - 
The spores and stylospores of Uredo come also upon the oe 
. mycelium, which had previously produced Æcidium. 
Uredo stylospores always produce Uredo and true spores.” 
I have thus, with slight alterations, followed the author at 

some length in the details of this singularly interesting seM> 
*Promycelium, the initiatory growth of the mycelium. 
a 

