can be generated
from them.

Obj. 3: Further, if any corporeal substance be generated from them,
such substance will not be without accident. Therefore, if any
corporeal substance be generated from the sacramental species, then
substance and accident would be generated from accident, namely, two
things from one, which is impossible. Consequently, it is impossible
for any corporeal substance to be generated out of the sacramental
species.

_On the contrary,_ The senses are witness that something is generated
out of the sacramental species, either ashes, if they be burned,
worms if they putrefy, or dust if they be crushed.

_I answer that,_ Since "the corruption of one thing is the generation
of another" (De Gener. i), something must be generated necessarily
from the sacramental species if they be corrupted, as stated above
(A. 4); for they are not corrupted in such a way that they disappear
altogether, as if reduced to nothing; on the contrary, something
sensible manifestly succeeds to them.

Nevertheless, it is difficult to see how anything can be generated
from them. For it is quite evident that nothing is generated out of
the body and blood of Christ which are truly there, because these are
incorruptible. But if the substance, or even the matter, of the bread
and wine were to remain in this sacrament, then, as some have
maintained, it would be easy to account for this sensible object
which succeeds to them. But that supposition is false, as was stated
above (Q. 75, AA. 2, 4, 8).

Hence it is that others have said that the things generated have not
sprung from the sacramental species, but from the surrounding
atmosphere. But this can be shown in many ways to be impossible. In
the first place, because when a thing is generated from another, the
latter at first appears changed and corrupted; whereas no alteration
or corruption appeared previously in the adjacent atmosphere; hence
the worms or ashes are not generated therefrom. Secondly, because the
nature of the atmosphere is not such as to permit of such things
being generated by such alterations. Thirdly, because it is possible
for many consecrated hosts to be burned or putrefied; nor would it be
possible for an earthen body, large enough to be generated from the
atmosphere, unless a great and, in fact, exceedingly sensible
condensation of the atmosphere took place. Fourthly, because the same
thing can happen to the solid bodies surrounding them, such as iron