Sequel to the Vestiges of: Creation. — 258 
gradating species are not to be found represented in the rocks— 
as for instance, between the birds and kangaroos, fishes and rep- 
tiles. We look in vain among the greatest variations of species 
at the present time for any approximation to such an amount of 
change, and the trifling modifications detected, only surprise us 
at the small limits of variation. But we leave the Acarus Crossti 
and the theory it supports, to those who can believe in it. 
If we mistake not, there is in the yery nature of animal and 
vegetable life, evidence against the “theory of progress.” An ani-_ 
mal is a piece of mechanism of divine origin. As in the mechan- 
isms of art, mechanical power is one result of its peculiar construc- 
tion, which is exhibited through the thousand levers that may 
be set at work. Besides, there are chemical compositions and de- 
compositions going on in every part, as another result of the 
powers within, or the battery of forces in action. By _ these 
means, the growth or sustentation of the animal takes place, and 
its physical energies are made manifest. But in addition to the 
compositions or reproductions going on throughout the system, 
there is another necessary result of its constitution, which is the 
reproduction of itself, or of germs equivalent to the same. ‘This 
result is far beyond that of other reproductions in the system. 
In the latter, only cellular tissue, or muscular tissue, or some less 
highly organized animal product, is concerned. But here, all the 
elements of the parent are engaged, the nervous, cellular and 
muscular, to bring out a result equivalent to the parent. This 
reproduction is a consequence of the mechanism, and maj 
considered as, physically, its prime result ; the animal forces with- 
in appear to have their point or points <a concentration, and the 
Same are the point or points of germ production. 
- Viewing an animal as thus constituted, have we any reason for 
believing that it ean produce a result superior to, or essentially 
different from, itself? Its reproductions must be limited to the 
extent of its powers. It may give origin to mechanisms inferior 
to itself, as the reproduction of muscular fibre exemplifies ; and 
perhaps the Entozoa (intestinal worms) may thus proceed through 
certain modifications. But can it accomplish a result beyond its 
energies? How can a baboon originate any thing above a ba- 
boon, with only a baboon’s mechanism. ‘The complete concen- 
tration of reproductive force takes place only in animals with a 
highly developed nervous system. As we descend in the scale, 
