irst sight seems to contradict the above
conclusions; but the _AEcidium_ which from the same disc produces the
puccinoid resting spores, appears to be different from the European
species, inasmuch as the cells of the wall of the sporangium are twice
as large, and the spores decidedly of greater diameter.[Z] The resting
spores, moreover, differ not only from those of _Puccinia graminis_,
but from those of all other European species.

From this account, then, it is extremely probable that the _AEcidium_
of the berberry enters into the cycle of existence of _Puccinia
graminis_, and, if this be true, wherefore should not other species
of _Puccinia_ be related in like manner to other _AEcidia_? This is the
conclusion to which many have arrived, and, taking advantage of
certain presumptions, have, we fear, rashly associated many such
forms together without substantial evidence. On the leaves of the
primrose we have commonly a species of _AEcidium_, _Puccinia_, and
_Uromyces_ nearly at the same time; we may imagine that all these
belong to one cycle, but it has not yet been proved. Again, _Uromyces
cacaliae_, Unger, _Uredo cacaliae_, Unger, and _AEcidium cacaliae_,
Thumen, are considered by Heufler[a] to form one cycle. Numerous
others are given by Fuckel,[b] and De Bary, in the same memoir from
which we have already cited, notes _Uromyces appendiculatus_, Link.,
_U. phaseolorum_, Tul., and _Puccinia tragopogonis_, Ca., as
possessing five kinds of reproductive organs. Towards the end of the
year, shortly stipitate spores appear on their stroma, which do not
fall off. These spores, which do not germinate till after a shorter
or longer winter rest, may conveniently be called resting spores, or,
as De Bary calls them, _teleutospores_, being the last which are
produced. These at length germinate, become articulated, and produce
ovate or kidney-shaped spores, which in their turn germinate,
penetrating the cuticle of the mother plant, avoiding the stomates or
apertures by which it breathes. After about two or three weeks,
the mycelium, which has ramified among the tissues, produces an
_AEcidium_, with its constant companion, spermogonia--distinct cysts,
that is, from which a quantity of minute bodies ooze out, often in
the form of a tendril, the function of which is imperfectly known at
present, but which from analogy we regard as a form of fruit,
though it is just possible that they may be rather of the nature of
spermatozoids. Th