See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1866
1872

OMIT 1869 1872
between the descendants from a common parent, 1859 1860 1861 1866

OMIT 1869 1872
are permitted to 1859 1860 1861 1866

finding the relations between 1869 1872
comparing 1859 1860 1861 1866

and another, 1869 1872
with a distinct group, 1859 1860 1861 1866

within a few great classes; 1869 1872
in one great system; 1859 1860 1861 1866

first 1869
are believed to have first 1872

On this idea of the natural system being, in so far as it has been perfected, genealogical in its arrangement, with the grades of difference OMIT expressed by the terms genera, families, orders, &c., we can understand the rules which we are compelled to follow in our classification. We can understand why we value certain resemblances far more than others; why we OMIT use rudimentary and useless organs, or others of trifling physiological importance; why, in finding the relations between one group and another, we summarily reject analogical or adaptive characters, and yet use
these
the
same characters within the limits of the same group. We can clearly see how it is that all living and extinct forms can be grouped together within a few great classes; and how the several members of each class are connected together by the most complex and radiating lines of affinities. We shall never, probably, disentangle the inextricable web of
affinities
the affinities
between the members of any one class; but when we have a distinct object in view, and do not look to some unknown plan of creation, we may hope to make sure but slow progress.
Professor Häckel in his 'Generelle
Morphologie'
Morphologic'
and in
several
several
other works, has recently brought his great knowledge and abilities to bear on what he calls phylogeny, or the lines of descent of all organic beings. In drawing up the several series he trusts chiefly to embryological characters, but
receives
draws
aid from homologous and rudimentary organs, as well as from the successive periods at which the various forms of life first appeared in our geological formations. He has thus boldly made a great beginning, and shows us how classification will in the future be treated.