NOMAD FUNGI. 
51 
farmer might breathe a sigh of relief, for perhaps his crops would 
never be attacked by rust or mildew again. But all is not yet lost: 
the fungus is equal to the occasion. Each cell of a puccinia-spore, 
germinating where it lies, sends out a short tube, forming at the end a 
few branches (usually two to four) into which the protoplasmic con¬ 
tents of the cell pass; the ends of these branches are constricted off, 
and we get two or three little round spores (the so-called sporidia), 
which are admirably adapted for being blown by the wind wheresoever 
it listeth. Imagine one of these tiny spheres alighting on a barberry 
leaf ; it germinates, sending out a germ-tube as before, but this time 
the tube does not seek for a stomate, but bores its way straight through 
the tender cuticle into the leaf. Here it forms a mycelium, from 
which, after a week or two, the (Ecidium is again produced. 
Thus the life-cycle is complete, and I venture to say that we have 
here as nice an instance of adaptation of means to ends, and as strange 
a story of transformation, as any which biology can furnish. This 
romantic tale is founded upon fact. Puccinia-spores have been sown 
upon barberry leaves and observed to germinate, and from the myce¬ 
lium thus produced an OEcidium has been seen to grow ; * similarly 
the production of the Ure lo from the oecidio-spores has been actually 
watched, while the production of a Puccinia from the same mycelium 
as the Uredo is a matter of easy observation. Thus, as in so many 
other instances, a common belief of country people, after enduring 
from so-called men of science the customary stages of incredulity and 
laughter, has now become an article of science ; and in a few years the 
man who dares to question it will be received with as much ridicule 
as were those who formerly believed it. The Norfolk farmers, and 
others, always held that the presence of barberry bushes in the hedges 
of their cornfields had something to do with the rust and mildew of 
their crops ; and this belief, though doubtless founded upon rough 
reasoning only, lurns out to be quite correct. Many other beliefs of 
country bumpkins, now held up to scorn as instances of superstition, 
will in future years become a part of the scientific creed. 
A perfect XJredinous fungus has, then, three distinct stages—the 
(Ecidium, the Uredo, and the Puccinia, distinguished by Continental 
mycologists as 1., II., and III., as will be seen by referring to the table 
of the revised classification on page 28. The spores of these are called, 
sometimes, protospores, stylospores, and teleutospores respectively; 
but the number of species in which all the three stages have been 
observed is comparatively few, and in the great majority either two or 
only one stage is at present known. 
It must not be supposed, however, that a Uredine which has all 
three stages need pass through them every year. Just as in Phanero¬ 
gams, a plant may have several modes of multiplication, of any of 
which it may avail itself according to circumstances. For instance, 
Mr. Plowright has shown that Puccinia poannn is a stage of (Ecidium 
* “ Grevillea,” xi. pp. 51-6. 
