of a bean or bindweed. In
_AEcidium Violae_, Schum, one filament is produced, which frequently
rolls up its anterior extremity into a spire, but more often this same
extremity rises in a large ovoid, irregular vesicle, which continues
the axis of the filament, or makes with it a more or less decided
angle. In whatever manner placed, this vesicle attracts to it all the
orange protoplasm, and hardly does this become settled and complete
before the vesicle becomes the starting point of a new development,
for it begins to produce at its apex a filament, more slender than the
previous one, stiff, and unbranched.

[Illustration: FIG. 81.--Germination of _AEcidium Euphorbia (sylvaticae)_,
Tulasne.]

According to M. Tulasne, the germination of the pseudospores of
_AEcidium Euphorbiae_ on _Euphorbia sylvatica_ differ in some respects
from the preceding. When dropped upon water these spores very soon
emit a short tube, which ordinarily curves in an arch or circle,
almost from its origin, attaining a length of from three to six times
the diameter of the spore; then this tube gives rise to four spicules,
each of which produces a small obovate or reniform sporule; the
generation of these sporules absorbs all the plastic matter contained
in the germ-tube, which permits of the observation that it was divided
into four cells corresponding with the number of spicules. These
sporules germinate very rapidly from an indefinite point of their
surface, emitting a filiform process, which is flexuous and very
delicate, not extending more in length than three times that of the
long axis of the sporule, often less, reproducing at its summit a new
sporule, differing in form and size from that which preceded it. This
sporule of the second formation becomes at its apex a vital centre,
and sprouts one or more linear buds, of which the elongation is
occasionally interrupted by the formation of vesicular swellings. As
Tulasne observes, the pseudospores of the _AEcidium_ and the greater
number of Uredines are easily wetted with water before arriving at
maturity; but when they are ripe, on the contrary, they appear to be
clothed with a greasy matter which protects them from the liquid,
forcing them almost all to rest on the surface.

The pseudospores of _Roestelia_ are produced in strings or chaplets,
as in _AEcidium_, with this difference, that instead of being
contiguous they are separated by narrow isthmuses. The ripe
pseudospores are enveloped i