| → the formation of 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
| → can be of any service 1859 1860 1861 1866 |
| are beneficial 1869 1872 |
|
| → the excretion of precious 1859 1860 1861 1866 |
| removing matter so precious as 1869 1872 |
|
| → sometimes 1859 1860 1861 1866 |
| have been known to 1869 1872 |
|
| → have appeared, not from unknown laws of growth, but 1859 1860 1861 1866 |
| have been developed 1869 |
| are developed 1872 |
|
| → were formed 1859 1860 1861 1866 |
| have been developed 1869 1872 |
|
| → simple. 1859 1860 1861 1866 1869 |
| comparatively simple; and we can understand to a large extent the laws governing their imperfect development. 1872 |
|
| → breeds,— 1859 1860 1861 1866 |
| breeds of sheep,— 1869 |
| breeds of sheep, 1872 |
|
| → monsters. 1859 1860 1861 1866 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 |
|
| → 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 |
| 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 |
|
| → to 1859 1860 1861 1866 |
| by beasts of prey to 1869 |
|
|
minute
which often
the pistil in male flowers, and which is formed
of
tissue, can thus act? Can we suppose that
→the formation of
rudimentary
which are subsequently absorbed,
→can be of any service
to the rapidly growing embryonic calf by
→the excretion of precious
phosphate of lime? When a
fingers have been amputated, imperfect nails
→sometimes
appear on the
could as soon believe that these vestiges of nails
→have appeared, not from unknown laws of growth, but
in order to excrete horny matter, as that the rudimentary nails on the fin of the manatee
→were formed
for this
|
|
| On
view of descent with modification, the origin of rudimentary organs is
→simple. 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,—
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 I doubt whether species under nature ever undergo abrupt changes. 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
|
