Origin of Species Variorum

→ of an astronomer who maintained that the satellites 1872

sufficient to say that because planets 1859 1860 1861 1866

of an astronomer, who maintained that the satellites 1869

→ their planets "for 1869 1872

the sun, satellites follow 1859 1860 1861 1866

→ of symmetry," because 1869 1872

course round 1859 1860 1861 1866

→ thus revolve round the sun? 1869 1872

for the sake of symmetry, and to complete the scheme of nature? 1859 1860 1861 1866

→ OMIT 1869 1872

the formation of 1859 1860 1861 1866

→ are beneficial 1869 1872

can be of any service 1859 1860 1861 1866

→ removing matter so precious as 1869 1872

the excretion of precious 1859 1860 1861 1866

→ have been known to 1869 1872

sometimes 1859 1860 1861 1866

→ are developed 1872

have appeared, not from unknown laws of growth, but 1859 1860 1861 1866

have been developed 1869

→ have been developed 1869 1872

were formed 1859 1860 1861 1866

→ comparatively simple; and we can understand to a large extent the laws governing their imperfect development. 1872

simple. 1859 1860 1861 1866 1869

→ breeds of sheep, 1872

breeds,— 1859 1860 1861 1866

breeds of sheep,— 1869

→ monsters; but I doubt whether any of these cases throw light on the origin of rudimentary organs in a state of nature, further than by showing that rudiments can be produced; for the balance of evidence clearly indicates that species under nature do not undergo great and abrupt changes. 1872

monsters. 1859 1860 1861 1866 1869

→ we learn from the study of our domestic productions that the disuse of parts leads to their reduced size; and that the result is inherited. 1872

I doubt whether any of these cases throw light on the origin of rudimentary organs in a state of nature, further than by showing that rudiments can be produced; for I doubt whether species under nature ever undergo abrupt changes. 1859 1860 1861 1866 1869

↑ 2 blocks not present in 1872; present in 1859 1860 1861 1866 1869

I believe that disuse has been the main agency; that it has led in successive generations to the gradual reduction of various organs, until they have become rudimentary,— as in the case of the eyes of animals inhabiting dark caverns, and of the wings of birds inhabiting oceanic islands, which have seldom been forced to take flight, and have ultimately lost the power of flying. Again, an organ useful under certain conditions, might become injurious under others, as with the wings of beetles living on small and exposed islands; and in this case natural selection would continue slowly to reduce the organ, until it was rendered harmless and rudimentary.

atrophied

organs,

organs

are imperfect and useless. In works on natural

history

history,

rudimentary organs are generally said to have been created "for the sake of symmetry," or in order "to complete the scheme of

nature;"

but

this

seems

explanation,

merely

an imposing

restatement

re-statement

....

the

....

fact.

....

But this is not an explanation, merely a re-statement of the fact. Nor is it consistent with itself: thus the boa-constrictor has rudiments of hind-limbs and of a pelvis, and if it be said that these bones have been retained "to complete the scheme of nature," why, as Professor Weismann asks, have they not been retained by other snakes, which do not possess even a vestige of these same bones?

Would it

What would

be thought →of an astronomer who maintained that the satellites revolve in elliptic courses round →their planets "for the

same

sake

→of symmetry," because

their

the

planets,

planets

→thus revolve round the sun? An eminent physiologist accounts for the presence of rudimentary organs, by supposing that they serve to excrete matter in excess, or

injurious

matter injurious

to the system; but can

suppose that the minute

papilla;

papilla,

which often

represent

represents

the pistil in male flowers, and which is formed

merely

....

cellular

mere cellular

tissue, can thus act? Can we suppose that →OMIT rudimentary

teeth

teeth,

which are subsequently absorbed, →are beneficial to the rapidly growing embryonic calf by →removing matter so precious as phosphate of lime? When a

mans

man's

fingers have been amputated, imperfect nails →have been known to appear on the

stumps:

stumps,

and I

could as soon believe that these vestiges of nails →are developed in order to excrete horny matter, as that the rudimentary nails on the fin of the manatee →have been developed for this

purpose.

same purpose.

the

view of descent with modification, the origin of rudimentary organs is →comparatively simple; and we can understand to a large extent the laws governing their imperfect development. We have plenty of cases of rudimentary organs in our domestic productions,— as the stump of a tail in tailless breeds,— the vestige of an ear in earless →breeds of sheep, the reappearance of minute dangling horns in hornless breeds of cattle, more especially, according to Youatt, in young animals,— and the state of the whole flower in the cauliflower. We often see rudiments of various parts in →monsters; but I doubt whether any of these cases throw light on the origin of rudimentary organs in a state of nature, further than by showing that rudiments can be produced; for the balance of evidence clearly indicates that species under nature do not undergo great and abrupt changes. But →we learn from the study of our domestic productions that the disuse of parts leads to their reduced size; and that the result is inherited. ↑

It appears probable that disuse has been the main agent in