
THE SMALLER FUNGI. 627 
orange protuberances, many of them surmounted by a little 
drop of mucilaginous fluid.» These are spermogones, daily. 
increasing in number, and soon after numerous large glob- 
ular protuberances intermingle with them. These soon rup- 
ture the skin of the leaf, and take the orange color and the 
form of cluster-cups, Æcidium. At length the summit of 
the peridia opens to allow the escape of the stylospores.* 
_ It is easy to assure oneself that the spermogones and the 
cluster-cups proceed from the same mycelium, and for some 
time to come the peridia of the Æcidium continue to in- 
crease, till at length brownish or blackish points make their 
appearance, intermingled with the cluster-cups, increasing 
rapidly in number and magnitude. Examined by the micro- 
scope they present the ordinary fructification of Uromyces 
mingled with stylospores. Thus the mycelium of the clus- 
ter-cups engenders, at the end of its vegetation, fruits equal 
in all points to those from whence, in the first instance, they 
are derived. These stylospores found in the cluster-cups 
possess the irregular globular form and structure of their 
congeners. If they should be sown on the moistened epider- 
mis (skin or cuticle) of a favorable plant, the sprouting or 
germ-tube at first creeps along the surface, but as soon as its 
extremities find a stomate,t it enters it, and elongates itself 
in the air-cavity{ below the orifice, receives the contents of 
the original stylospore and exposed portion of its tube, then 
Separates itself from those parts which become dispersed. 
The active part increases and ramifies, and produces à 
mycelium which spreads through ‘the. intercellular passages 
of the parenchyma (pulp). Whitish spots subsequently 
appear on the surface of the fostering plant, and indicate 
that the fructification of the parasite is about to commence. 
The epidermis is elevated and broken, and little brown pus- 
tules appear through the openings. These are the stylo- 
*Stylospores, a second kind of spores borne on long threads, enclosed in a peri 
Or appropriate pustule 
‘18tomate, breathing-pore of the leat, tAir-onviy, a space in thé pulp of the leet 
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