—
—
NATURE
io6
most probable that " life, like matter and origin in no secondary cause, but in the Chapters X. to XIV. direct action of creative power." treat of organisation and development, and give a summary of the most recent views on these subjects, confacts render
it
energy, had
its
cluding with the following tabular statement of organic functions
roimativc or Vegetative Functions, essentially consisting in the Transformation of Matter. Formation of organic compounds. Chemical Formation of tissue. o. , Structural r ,, V ormation of organs. ,
(
,
<,
Fnnctions, consisting essentially in the Transformation
Reflex.
1 ( (
Sensory.
(
and we then come
to the causes of
25,
1869
development, in which
the author explains his views as follows
These two causes, self-adaptation and natural selection, are the o-A^ purely physical causes that have been assigned, or that appear assignable, for the origin of organic structure and form. But I believe they will account for only part of the facts, and that no solution of the questions of the origin of organization, and the origin of organic species, can be adequate, which does not recognise an Organising Intelligence, over and above the common laws of matter But we must begin the inquiry by considering hoio much of the facts of organic structure and ital function may be accounted for by the tvo laws of self-adaptation and natural selection, before we assert that any of those facts can
Again
of Energy. I Spontaneous.
Motor.
Nov.
only be accounted for by supposing an Organising Intelligence.
(
Animal
—
Consensual. Voluntary. Sensation. jMind.
Life does not suspend the action of the ordinary forces of matter, but works through them. I believe that wherever there is life there is intelligence, and that intelligence is at work in every whatever, vital process but most disccrnibly in the highest. . . Nutrition, circulation, and respiration are in a great degree to be explained as results of ])hysical and chemical laws ; but sensation, perception, and thought cannot be so explained. They belong exclusively to life; and similarly the organs of those functions the nerves, the brain, the eje, and the ear can have originated, I believe, solely by the action of an Organising Intelligence. .
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we first come to one of the author's special subjects, — the Laws of Habit. He defines habit as follows " The definition of habit and its primary In the fifteenth chapter
—
law,
that all vital actions tend to repeat themselves they are not such as can repeat themselves, they
is
or, if
tend to become easier on repetition." or less hereditary, are
All habits are more somewhat changeable by circum-
and are subject to spontaneous variations. The prominence of a habit depends upon its having been recently exercised its tenacity on the length of time stances,
-
(millions of generations
it
may
be) during ^vhich
it
has
been exercised. The habits of the species or genus are most tenacious, those of the individual often the most prominent. The latter may be quickly lost, the former may appear to be lost, but are often latent, and are liable to reappear, as in cases of reversion.
The
habits are strengthened, while passive
weakened, by
fact that active
impressions are
due in both cases to the law of habit for, in the latter, the organism acquires the habit of not responding to the impression. As an example, two men hear the same loud bell in the morning it calls the one to work, as he is accustomed to listen to it, and so it always wakes him the otherhas to rise an hour later, he is accustomed to disregard it, and so it soon ceases to have any effect upon him. Habit has produced in these two cases exactly opposite results. Habits are capable of any amount of change, but only a slight change is possible in a short time and in close relation with this law are repetition,
the following laws of variation.
Changes of external circumstances are if
great, unless
they are slight
made
but injurious
beneficial to if
th.v arc
gradually.
Changes of external circumstances are agreeable when slight,
but disagreeable
when
IMixture of different races
the offspring
if
theory will account for the origin of the special complexities of the visual apparatus
Neither the action of light on the eye, nor the actions of tlie eye itself, can have the slightest tendency to produce the wondrous complex histological structure of the retina nor to form the transparent humours of the eye into lenses; nor to protluce tlie deposit of black 'pigment that absorbs the stray rays that ^^ould otherwise hinder clear vision; nor to produce the iris, and endow it with its power of closing under a strong light, so as to protect the retina, and expanding again when the light is withdrawn nor to give the iris its two nervous connections, one of which has its root in the sympatlietic ganglia, and 'causes expansion, while the other has its root in the brain and causes contraction.
is
organisms
Admitting Mr.Ilerbert Spencer's theory of the origin of the vascular system, and possibly of the muscular, by scJf-adaptation, he denies that any such merely physical
great.
is
beneficial to the vigour of
the races mixed are but slightly different
while very different races will produce either
weak
offsjiring,
or infertile offspring, or none at all. Even the great law of sexuaUty, requiring the union of slightly different individuals to continue the race, seems to stand in close
connection with the preceding laws. The next seven chapters treat of the laws of variation, distribution, morphology, embryology, and classification, as all pointing to the origin of species by development
Nor will he allow that Natural Selection (which he admits may produce any simple organ, such as a bat's wing) is applicable to this case ; and he makes use of two arguments which have considerable weight. One is that of Mr. Herbert Spencer, who shows that in all the higher animals natural selection must be aided by self-adaptation, because an alteration in any part of a complex organ necessitates concomitant alterations in many other parts, and these cannot be supposed to occur by spontaneous variation. But in the case of the eye he shows that selfadaptation cannot occur, whence he conceives it may be proved to be almost an infinity of chances to one against the simultaneous variations necessary to produce an eye ever having occurred. The other argument is, that welldeveloped eyes occur in the higher orders of the three great groups, Annulosa, Mollusca, and Vertebrata, wdiile the lower orders of each hae rudimentary e-es or none so that the variations requisite to produce this wonderfully complicated organ must have occurred three times over independently of each other. In the first of these objections, he assumes that many variations must occur simul;
taneously,
He
and on this assumption his wdiole argument rests.
notices Mr. Darwin's illustration of the greyhound
having been brotight to its present high state of perfection by breeders selecting for one point at a time, but does not think it possible " that any apparatus, consisting of lenses,
