theory could be so far-fetched
or fantastical as not to attract some followers, provided it fell in
with popular notions; and as cosmogonists were not at all restricted, in
building their systems, to the agency of known causes, the opponents of
Fracastoro met his arguments by feigning imaginary causes, which
differed from each other rather in name than in substance. Andrea
Mattioli, for instance, an eminent botanist, the illustrator of
Dioscorides, embraced the notion of Agricola, a skilful German miner,
that a certain "materia pinguis," or "fatty matter," set into
fermentation by heat, gave birth to fossil organic shapes. Yet Mattioli
had come to the conclusion, from his own observations, that porous
bodies, such as bones and shells, might be converted into stone, as
being permeable to what he termed the "lapidifying juice." In like
manner, Falloppio of Padua conceived that petrified shells were
generated by fermentation in the spots where they are found, or that
they had in some cases acquired their form from "the tumultuous
movements of terrestrial exhalations." Although celebrated as a
professor of anatomy, he taught that certain tusks of elephants, dug up
in his time in Apulia, were mere earthy concretions; and, consistently
with these principles, he even went so far as to consider it probable,
that the vases of Monte Testaceo at Rome were natural impressions
stamped in the soil.[43] In the same spirit, Mercati, who published, in
1574, faithful figures of the fossil shells preserved by Pope Sixtus V.
in the Museum of the Vatican, expressed an opinion that they were mere
stones, which had assumed their peculiar configuration from the
influence of the heavenly bodies; and Olivi of Cremona, who described
the fossil remains of a rich museum at Verona, was satisfied with
considering them as mere "sports of nature."

Some of the fanciful notions of those times were deemed less
unreasonable, as being somewhat in harmony with the Aristotelian theory
of spontaneous generation, then taught in all the schools.[44] For men
who had been taught in early youth, that a large proportion of living
animals and plants was formed from the fortuitous concourse of atoms, or
had sprung from the corruption of organic matter, might easily persuade
themselves that organic shapes, often imperfectly preserved in the
interior of solid rocks, owed their existence to causes equally obscure
and mysterious.

_Cardano_, 1552.--But there were not