)
In 1853 a celebrated geologist, Count Keyserling ("Bulletin de la Soc.
Geolog.", 2nd Ser., tom. x, page 357), suggested that as new diseases,
supposed to have been caused by some miasma have arisen and spread over the
world, so at certain periods the germs of existing species may have been
chemically affected by circumambient molecules of a particular nature, and
thus have given rise to new forms.
In this same year, 1853, Dr. Schaaffhausen published an excellent pamphlet
("Verhand. des Naturhist. Vereins der Preuss. Rheinlands", etc.), in which
he maintains the development of organic forms on the earth. He infers that
many species have kept true for long periods, whereas a few have become
modified. The distinction of species he explains by the destruction of
intermediate graduated forms. "Thus living plants and animals are not
separated from the extinct by new creations, but are to be regarded as
their descendants through continued reproduction."
A well-known French botanist, M. Lecoq, writes in 1854 ("Etudes sur
Geograph. Bot. tom. i, page 250), "On voit que nos recherches sur la fixite
ou la variation de l'espece, nous conduisent directement aux idees emises
par deux hommes justement celebres, Geoffroy Saint-Hilaire et Goethe."
Some other passages scattered through M. Lecoq's large work make it a
little doubtful how far he extends his views on the modification of
species.
Pages:
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34