Vv. VARIETIES, ETC. 49 
incidental one in the pamphlet from which they are extracted. 
The more matured views of the same writer were set forth in 
papers in the Phytologist for 1815, and partially copied thence 
into the Cybele Britannica, volume 4, pages 59—63. They afford 
a fair sample of the state of the question in the years that inter- 
vened between the date of the ‘ Vestiges’ and that of the ‘ Origin 
of Species by means of Natural Selection.’ At same time, a full 
conviction of the truth of the transition-of-species theory is not 
declared ; in either instance cited, being evidently withheld from 
lack of the one key or explanation which Mr. Darwin has brought 
to its support, whether successfully or unsuccessfully so brought, 
under the designation of “ Natural Selection.” 
The distinctive peculiarity of the Darwinian theory, is, that its 
Author has much more fully and clearly explained how (in his 
view) the changes between past and present life on the earth 
could have been brought about, and this in a manner so gradual 
and unobtrusive that it is even yet going on around us in ceaseless 
progress, long unobserved by most of us, imperfectly recognized 
by a very few, clearly and fully detected by none before Mr. 
Darwin himself took up the subject. By giving a name to this 
hitherto nameless process of nature, most ably marshalling an 
ample array of illustrative details, all more or less intimately 
bearing upon his leading principle of “ natural selection,” he has 
perhaps achieved the greatest advance in natural science that ever 
has been achieved by one individual. 
What is the real advance? It is familiar even to triteness that 
variations do arise among animals and plants, and that some of 
these variations do tend to become hereditary, by re-appearing in a 
second generation, and so on to succeeding generations. It is 
well known, too, that the progeny of the variety will often also 
apparently tend back, by reproducing the original ancestral like- 
ness, more or less perfectly, instead of its own altered likeness or 
“characters.” Here are two seeming tendencies, both inferred 
from actual facts; the preponderance of one keeping up the 
species ; the preponderance of the other keeping up its varicties. 
In the long run, which of the two tendencies will prevail, and 
H 
