The Foundations of the Origin of Species Part 7

{159} An almost identical pa.s.sage occurs in the _Origin_, Ed. i. p.

440, vi. p. 606.

Light can be thrown on this by our theory. The structure of each organism is chiefly adapted to the sustension of its life, when full-grown, when it has to feed itself and propagate{160}. The structure of a kitten is quite in secondary degree adapted to its habits, whilst fed by its mother's milk and prey. Hence variation in the structure of the full-grown species will _chiefly_ determine the preservation of a species now become ill-suited to its habitat, or rather with a better place opened to it in the economy of Nature. It would not matter to the full-grown cat whether in its young state it was more or less eminently feline, so that it become so when full-grown. No doubt most variation, (not depending on habits of life of individual) depends on early change{161} and we must suspect that at whatever time of life the alteration of foetus is effected, it tends to appear at same period.

When we a tendency to particular disease in old age transmitted by the male, we know some effect is produced during conception, on the simple cell of ovule, which will not produce its effect till half a century afterwards and that effect is not visible{162}. So we see in grey-hound, bull-dog, in race-horse and cart-horse, which have been selected for their form in full-life, there is much less (?) difference in the few first days after birth{163}, than when full-grown: so in cattle, we see it clearly in cases of cattle, which differ obviously in shape and length of horns. If man were during 10,000 years to be able to select, far more diverse animals from horse or cow, I should expect there would be far less differences in the very young and foetal state: and this, I think, throws light on above marvellous fact. In larvae, which have long life selection, perhaps, does much,--in the pupa not so much{164} There is no object gained in varying form &c. of foetus (beyond certain adaptations to mother's womb) and therefore selection will not further act on it, than in giving to its changing tissues a tendency to certain parts afterwards to a.s.sume certain forms.

{160} The following: "Deaths of brothers old by same peculiar disease" which is written between the lines seems to have been a memorandum which is expanded a few lines lower. I believe the case of the brothers came from Dr R. W. Darwin.

{161} See the discussion to this effect in the _Origin_, Ed. i. pp.

443-4, vi. p. 610. The author there makes the distinction between a cause affecting the germ-cell and the reaction occurring at a late period of life.

{162} Possibly the sentence was meant to end "is not visible till then."

{163} See _Origin_, Ed. i. pp. 444-5, vi. p. 611. The query appended to _much less_ is justified, since measurement was necessary to prove that the greyhound and bulldog puppies had not nearly acquired "their full amount of proportional difference."

{164} I think light can be thrown on these facts. From the following peculiarities being hereditary, [we know that some change in the germinal vesicle is effected, which will only betray itself years after] diseases--man, goitre, gout, baldness, fatness, size, [longevity time of reproduction, shape of horns, case of old brothers dying of same disease]. And we know that the germinal vesicle must have been affected, though no effect is apparent or can be apparent till years afterwards,--no more apparent than when these peculiarities appear by the exposure of the full-grown individual. So that when we see a variety in cattle, even if the variety be due to act of reproduction, we cannot feel sure at what period this change became apparent. It may have been effected during early age of free life foetal existence, as monsters show. From arguments before used, and crossing, we may generally suspect in germ; but I repeat it does not follow, that the change should be apparent till life fully developed; any more than fatness depending on heredity should be apparent during early childhood, still less during foetal existence. In case of horns of cattle, which when inherited must depend on germinal vesicle, obviously no effect till cattle full-grown. Practically it would appear that the [hereditary]

peculiarities characterising our domestic races, therefore resulting from vesicle, do not appear with their full characters in very early states; thus though two breeds of cows have calves different, they are not so different,--grey-hound and bull-dog.

And this is what is be expected, for man is indifferent to characters of young animals and hence would select those full-grown animals which possessed the desirable characteristics. So that from mere chance we might expect that some of the characters would be such only as became fully apparent in mature life. Furthermore we may suspect it to be a law, that at whatever time a new character appears, whether from vesicle, or effects of external conditions, it would appear at corresponding time .

Thus diseases appearing in old age produce children with d^o.,--early maturity,--longevity,--old men, brothers, of same disease--young children of d^o. I said men do not select for quality of young,--calf with big bullocks. Silk-worms, peculiarities which, appear in caterpillar state or coc.o.o.n state, are transmitted to corresponding states. The effect of this would be that if some peculiarity was born in a young animal, but never exercised, it might be inherited in young animal; but if exercised that part of structure would be increased and would be inherited in corresponding time of life after such training.

I have said that man selects in full-life, so would it be in Nature. In struggle of existence, it matters nothing to a feline animal, whether kitten eminently feline, as long as it sucks.

Therefore natural selection would act equally well on character which was fully only in full age. Selection could tend to alter no character in foetus, (except relation to mother) it would alter less in young state (putting on one side larva condition) but alter every part in full-grown condition. Look to a foetus and its parent, and again after ages foetus and its descendant; the parent more variable than foetus, which explains all.]

Thus there is no power to change the course of the arteries, as long as they nourish the foetus; it is the selection of slight changes which supervene at any time during of life.

The less differences of foetus,--this has obvious meaning on this view: otherwise how strange that a [monkey] horse, a man, a bat should at one time of life have arteries, running in a manner, which is only intelligibly useful in a fis.h.!.+ The natural system being on theory genealogical, we can at once see, why foetus, retaining traces of the ancestral form, is of the highest value in cla.s.sification.

-- IX.

There is another grand cla.s.s of facts relating to what are called abortive organs. These consist of organs which the same reasoning power that shows us how beautifully these organs in some cases are adapted to certain end, declares in other cases are absolutely useless. Thus teeth in Rhinoceros{165}, whale, narwhal,--bone on tibia, muscles which do not move,--little bone of wing of Apteryx,--bone representing extremities in some snake,--little wings within soldered cover of beetles,--men and bulls, mammae: filaments without anthers in plants, mere scales representing petals in others, in feather-hyacinth whole flower. Almost infinitely numerous. No one can reflect on these without astonishment, can anything be clearer than that wings are to fly and teeth , and yet we find these organs perfect in every detail in situations where they cannot possibly be of their normal use{166}.

{165} Some of these examples occur in _Origin_, Ed. i. pp. 450-51, vi. pp. 619-20.

{166} The two following sentences are written, one down the margin, the other across the page. "Abortive organs eminently useful in cla.s.sification. Embryonic state of organs. Rudiments of organs."

The term abortive organ has been thus applied to above structure (as _invariable_ as all other parts{167}) from their absolute similarity to monstrous cases, where from _accident_, certain organs are not developed; as infant without arms or fingers with mere stump representing them: teeth represented by mere points of ossification: headless children with mere b.u.t.ton,--viscera represented by small amorphous ma.s.ses, &c.,--the tail by mere stump,--a solid horn by minute hanging one{168}. There is a tendency in all these cases, when life is preserved, for such structures to become hereditary. We see it in tailless dogs and cats. In plants we see this strikingly,--in Thyme, in _Linum flavum_,--stamen in _Geranium pyrenaic.u.m_{169}. Nectaries abort into petals in Columbine <_aquilegia_>, produced from some accident and then become hereditary, in some cases only when propagated by buds, in other cases by seed. These cases have been produced suddenly by accident in early growth, but it is part of law of growth that when any organ is not used it tends to diminish (duck's wing{170}?) muscles of dog's ears, readily explain the fact, so astounding on any other view, namely that organs possibly useless have been formed often with the same exquisite care as when of vital importance.

{167} I imagine the meaning to be that abortive organs are specific characters in contrast to monstrosities.

{168} Minute hanging horns are mentioned in the _Origin_, Ed. i. p.

454, vi. p. 625, as occurring in hornless breeds of cattle.

{169} _Linum flavum_ is dimorphic: thyme gynodiaecious. It is not clear what point is referred to under _Geranium pyrenaic.u.m_.

{170} The author's work on duck's wings &c. is in _Var. under Dom._, Ed. 2, i. p. 299.

{171} The words _vis medicatrix_ are inserted after "useless,"

apparently as a memorandum.

Our theory, I may remark would permit an organ become abortive with respect to its primary use, to be turned to any other purpose, (as the buds in a cauliflower) thus we can see no difficulty in bones of male marsupials being used as fulcrum of muscles, or style of marygold{172},--indeed in one point of view, the heads of [vertebrated]

animal may be said to be abortive vertebrae turned into other use: legs of some crustacea abortive jaws, &c., &c. De Candolle's a.n.a.logy of table covered with dishes{173}.

{172} In the male florets of certain Compositae the style functions merely as a piston for forcing out the pollen.

{173} If abortive organs are a trace preserved by hereditary tendency, of organ in ancestor of use, we can at once see why important in natural cla.s.sification, also why more plain in young animal because, as in last section, the selection has altered the old animal most. I repeat, these wondrous facts, of parts created for no use in past and present time, all can by my theory receive simple explanation; or they receive none and we must be content with some such empty metaphor, as that of De Candolle, who compares creation to a well covered table, and says abortive organs may be compared to the dishes (some should be empty) placed symmetrically!

Degradation and complication see Lamarck: no tendency to perfection: if room, [even] high organism would have greater power in beating lower one, thought to be selected for a degraded end.

-- X. RECAPITULATION AND CONCLUSION.

Let us recapitulate the whole these latter sections by taking case of the three species of Rhinoceros, which inhabit Java, Sumatra, and mainland of Malacca or India. We find these three close neighbours, occupants of distinct but neighbouring districts, as a group having a different aspect from the Rhinoceros of Africa, though some of these latter inhabit very similar countries, but others most diverse stations.

We find them intimately related [scarcely differences more than some breeds of cattle] in structure to the Rhinoceros, which for immense periods have inhabited this one, out of three main zoological divisions of the world. Yet some of these ancient animals were fitted to very different stations: we find all three of the generic character of the Rhinoceros, which form a [piece of net]{174} set of links in the broken chain representing the Pachydermata, as the chain likewise forms a portion in other and longer chains. We see this wonderfully in dissecting the coa.r.s.e leg of all three and finding nearly the same bones as in bat's wings or man's hand, but we see the clear mark in solid tibia of the fusion into it of the fibula. In all three we find their heads composed of three altered vertebrae, short neck, same bones as giraffe. In the upper jaws of all three we find small teeth like rabbit's. In dissecting them in foetal state we find at a not very early stage their form exactly alike the most different animals, and even with arteries running as in a fish: and this similarity holds when the young one is produced in womb, pond, egg or sp.a.w.n. Now these three undoubted species scarcely differ more than breeds of cattle, are probably subject to many the same contagious diseases; if domesticated these forms would vary, and they might possibly breed together, and fuse into something{175} different their aboriginal forms; might be selected to serve different ends.

{174} The author doubtless meant that the complex relations.h.i.+ps between organisms can be roughly represented by a net in which the knots stand for species.

{175} Between the lines occurs:--"one form be lost."

Now the Creationist believes these three Rhinoceroses were created{176} with their deceptive appearance of true, not relations.h.i.+p; as well can I believe the planets revolve in their present courses not from one law of gravity but from distinct volition of Creator.

{176} The original sentence is here broken up by the insertion of:--"out of the dust of Java, Sumatra, these allied to past and present age and , with the stamp of inutility in some of their organs and conversion in others."

If real species, sterile one with another, differently adapted, now inhabiting different countries, with different structures and instincts, are admitted to have common descent, we can only legitimately stop where our facts stop. Look how far in some case a chain of species will lead us. May we not jump (considering how much extermination, and how imperfect geological records) from one sub-genus to another sub-genus. Can genera restrain us; many of the same arguments, which made us give up species, inexorably demand genera and families and orders to fall, and cla.s.ses tottering. We ought to stop only when clear unity of type, independent of use and adaptation, ceases.

Be it remembered no naturalist pretends to give test from external characters of species; in many genera the distinction is quite arbitrary{177}. But there remains one other way of comparing species with races; it is to compare the effects of crossing them. Would it not be wonderful, if the union of two organisms, produced by two separate acts of Creation, blended their characters together when crossed according to the same rules, as two races which have undoubtedly descended from same parent stock; yet this can be shown to be the case.

For sterility, though a usual , is not an invariable concomitant, it varies much in degree and has been shown to be probably dependent on causes closely a.n.a.logous with those which make domesticated organisms sterile. Independent of sterility there is no difference between mongrels and hybrids, as can be shown in a long series of facts. It is strikingly seen in cases of instincts, when the minds of the two species or races become blended together{178}. In both cases if the half-breed be crossed with either parent for a few generations, all traces of the one parent form is lost (as Kolreuter in two tobacco species almost sterile together), so that the Creationist in the case of a species, must believe that one act of creation is absorbed into another!

{177} Between the lines occur the words:--"Species vary according to same general laws as varieties; they cross according to same laws."

{178} "A cross with a bull-dog has affected for many generations the courage and obstinacy of greyhounds," _Origin_, Ed. i. p. 214, vi. p. 327.

{Ill.u.s.tration: Facsimile of the original ma.n.u.script of the paragraph on p. 50.}

CONCLUSION.

Such are my reasons for believing that specific forms are not immutable.

The affinity of different groups, the unity of types of structure, the representative forms through which foetus pa.s.ses, the metamorphosis of organs, the abortion of others cease to be metaphorical expressions and become intelligible facts. We no longer look

How interesting does the distribution of all animals become, as throwing light on ancient geography. [We see some seas bridged over.] Geology loses in its glory from the imperfection of its archives{181}, but how does it gain in the immensity of the periods of its formations and of the gaps separating these formations. There is much grandeur in looking at the existing animals either as the lineal descendants of the forms buried under thousand feet of matter, or as the coheirs of some still more ancient ancestor. It accords with what we know of the law impressed on matter by the Creator, that the creation and extinction of forms, like the birth and death of individuals should be the effect of secondary [laws] means{182}. It is derogatory that the Creator of countless systems of worlds should have created each of the myriads of creeping parasites and [slimy] worms which have swarmed each day of life on land and water [this] one globe. We cease being astonished, however much we may deplore, that a group of animals should have been directly created to lay their eggs in bowels and flesh of other,--that some organisms should delight in cruelty,--that animals should be led away by false instincts,--that annually there should be an incalculable waste of eggs and pollen. From death, famine, rapine, and the concealed war of nature we can see that the highest good, which we can conceive, the creation of the higher animals has directly come. Doubtless it at first transcends our humble powers, to conceive laws capable of creating individual organisms, each characterised by the most exquisite workmans.h.i.+p and widely-extended adaptations. It accords better with [our modesty] the lowness of our faculties to suppose each must require the fiat of a creator, but in the same proportion the existence of such laws should exalt our notion of the power of the omniscient Creator{183}.

There is a simple grandeur in the view of life with its powers of growth, a.s.similation and reproduction, being originally breathed into matter under one or a few forms, and that whilst this our planet has gone circling on according to fixed laws, and land and water, in a cycle of change, have gone on replacing each other, that from so simple an origin, through the process of gradual selection of infinitesimal changes, endless forms most beautiful and most wonderful have been evolved{184}.

{179} The simile of the savage and the s.h.i.+p occurs in the _Origin_, Ed. i. p. 485, vi. p. 665.

{180} In the _Origin_, Ed. i. p. 486, vi. p. 665, the author speaks of the "summing up of many contrivances": I have therefore introduced the above words which make the pa.s.sage clearer. In the _Origin_ the comparison is with "a great mechanical invention,"--not with a work of art.

{181} See a similar pa.s.sage in the _Origin_, Ed. i. p. 487, vi. p.

667.