Origin of Species Variorum

→ other , 1872

other, 1859

other , 1860 1861

other, 1866 1869

→ a few grand classes; 1869 1872

one grand natural system; 1859 1860 1861 1866

→ extinct species can all 1872

all fossils can 1859 1860 1861 1866

all extinct species can 1869

→ is certainly true; but as this statement has often been ignored or even denied, it may be well to make some remarks on this subject, and to give some instances. 1872

cannot be disputed. 1859 1860 1861 1866 1869

→ species of the same class, 1872

alone, 1859 1860 1861 1866 1869

→ In the writings of Professor Owen we continually meet with the expression of generalised forms, as applied to 1872

With respect to the Vertebrata, whole pages could be filled with striking illustrations from our great palæontologist, Owen, showing how 1859 1860 1861

With respect to the vertebrata, whole pages could be filled with striking illustrations from our great palæontologist, Owen, showing how 1866

With respect to the vertebrata, whole pages could be filled with illustrations from Owen, showing how 1869

→ the writings of Agassiz, of prophetic or synthetic types; and these terms imply that such forms are in fact intermediate or connecting links. 1872

between existing groups. 1859 1860 1861 1866 1869

→ two of the 1872

the two 1859 1860 1861 1866 1869

→ OMIT 1872

Owen has discovered 1859 1860 1861 1866 1869

→ have been disentombed that Owen 1872

that he 1859 1860 1861 1866 1869

→ OMIT 1869 1872

of these two orders; 1859 1860 1861 1866

→ has shown in the most striking manner that 1872

shows that very 1869

→ serve to break down the intervals between 1872

connect in the plainest manner 1869

compares certain stages in England with those in France, although he finds in both a curious accordance in the numbers of the species belonging to the same genera, yet the species themselves differ in a manner very difficult to account

for,

for

considering the proximity of the two areas,—

unless

unless,

indeed, it be assumed that an isthmus separated two seas inhabited by distinct, but contemporaneous, faunas. Lyell has made similar observations on some of the later tertiary formations. Barrande, also, shows that there is a striking general parallelism in the successive Silurian deposits of Bohemia and Scandinavia; nevertheless he finds a surprising amount of difference in the species. If the several formations in these regions have not been deposited during the same exact periods,— a formation in one region often corresponding with a blank interval in the other,— and if in both regions the species have gone on slowly changing during the accumulation of the several formations and during the long intervals of time between them; in this

case,

case

the several formations in the two regions could be arranged in the same order, in accordance with the general succession of the

form

forms

of life, and the order would falsely appear to be strictly parallel; nevertheless the species would not

all be

be all

the same in the apparently corresponding stages in the two regions.

the

Affinities

extinct

Extinct

Species

each

→ other ,

and

living

Living

forms .—

forms. —

Forms.

Forms .

Let us now look to the mutual affinities of extinct and living species.

They

All

all

fall

....

into →a few grand classes; and this fact is at once explained on the principle of descent. The more ancient any form is, the more, as a general rule, it differs from living forms. But, as Buckland long ago remarked, →extinct species can all be classed either in still existing groups, or between them. That the extinct forms of life help to fill up the

wide

....

intervals between existing genera, families, and orders, →is certainly true; but as this statement has often been ignored or even denied, it may be well to make some remarks on this subject, and to give some instances.

For if

we confine our attention either to the living or to the extinct →species of the same class, the series is far less perfect than if we combine both into one general system. →In the writings of Professor Owen we continually meet with the expression of generalised forms, as applied to extinct

animals

animals;

fall

and

in →the writings of Agassiz, of prophetic or synthetic types; and these terms imply that such forms are in fact intermediate or connecting links. Cuvier ranked the Ruminants and Pachyderms, as →two of the most distinct orders of

mammals;

mammals:

but →OMIT so many fossil

links,

links

→have been disentombed that Owen has had to alter the whole

classification

classification,

→OMIT and has placed certain pachyderms in the same sub-order with

ruminants:

ruminants;

for example, he dissolves by

fine

....

gradations the apparently wide

difference

interval

between the pig and the camel. The Ungulata or hoofed quadrupeds are now divided into the even-toed or odd-toed divisions; but the Macrauchenia of S. America connects to a certain extent these two grand divisions. No one will deny that the Hipparion is intermediate between the existing horse and certain older ungulate forms. What a wonderful connecting link in the chain of mammals is the Typotherium from S. America, as the name given to it by Professor Gervais expresses, and which cannot be placed in any existing order. The Sirenia form a very distinct group of mammals, and one of the most remarkable peculiarities in the existing dugong and lamentin is the entire absence of hind limbs, without even a rudiment being left; but the extinct Halitherium had, according to Professor Flower, an ossified thigh-bone "articulated to a well-defined acetabulum in the pelvis," and it thus makes some approach to ordinary hoofed quadrupeds, to which the Sirenia are in other respects allied. The cetaceans or whales are widely different from all other mammals, but the tertiary Zeuglodon and Squalodon, which have been placed by some naturalists in an order by themselves, are considered by Professor Huxley to be undoubtedly cetaceans, "and to constitute connecting links with the aquatic carnivora." Another distinguished palæontologist, M. Gaudry, →has shown in the most striking manner that many of the fossil mammals discovered by him in Attica →serve to break down the intervals between existing genera.