als and Plants under
Domestication."--Difficulties of the Darwinian theory enumerated ... _Page_
1

CHAPTER II.

_THE INCOMPETENCY OF "NATURAL SELECTION" TO ACCOUNT FOR THE INCIPIENT
STAGES OF USEFUL STRUCTURES._

Mr. Darwin supposes that Natural-Selection acts by slight
variations.--These must be useful at once.--Difficulties as to the giraffe;
as to mimicry; as to the heads of flat-fishes; as to the origin and
constancy of the vertebrate, limbs; as to whalebone; as to the young
kangaroo; as to sea-urchins; as to certain processes of {viii}
metamorphosis; as to the mammary gland; as to certain ape characters; as to
the rattlesnake and cobra; as to the process of formation of the eye and
ear; as to the fully developed condition of the eye and ear; as to the
voice; as to shell-fish; as to orchids; as to ants.--The necessity for the
simultaneous modification of many individuals.--Summary and conclusion ...
_Page_ 23

CHAPTER III.

_THE CO-EXISTENCE OF CLOSELY SIMILAR STRUCTURES OF DIVERSE ORIGIN._

Chances against concordant variations.--Examples of discordant
ones.--Concordant variations not unlikely on a non-Darwinian evolutionary
hypothesis.--Placental and implacental mammals.--Birds and
reptiles.--Independent origins of similar sense organs.--The ear.--The
eye.--Other coincidences.--Causes besides Natural Selection produce
concordant variations in certain geographical regions.--Causes besides
Natural Selection produce concordant variations in certain zoological and
botanical groups.--There are homologous parts not genetically
related.--Harmony in respect of the organic and inorganic worlds.--Summary
and conclusion ... _Page_ 63

CHAPTER IV.

_MINUTE AND GRADUAL MODIFICATIONS._

There are difficulties as to minute modifications, even if not
fortuitous.--Examples of sudden and considerable modifications of different
kinds.--Professor Owen's view.--Mr. Wallace.--Professor Huxley.--Objections
to sudden changes.--Labyrinthodont.--Potto.--Cetacea.--As to origin of
bird's wing.--Tendrils of climbing plants.--Animals once supposed to be
connecting links.--Early specialization of
structure.--Macrauchenia.--Glyptodon.--Sabre-toothed tiger.--Conclusion ...
_Page_ 97

{ix}
CHAPTER V.

_AS TO SPECIFIC STABILITY._

What is meant by the phrase "specific stability;" such stability to be
expected _a priori_, or else considerable chang