The foundations of The origin of species : a sketch written in 1842 / edited by Francis Darwin.
- Charles Darwin
- Date:
- 1909
Licence: Public Domain Mark
Credit: The foundations of The origin of species : a sketch written in 1842 / edited by Francis Darwin. Source: Wellcome Collection.
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![But we can see that if this carried to extreme, unity lost,—Plesiosaurus. Here we have seen the same organ is formed (?) (for) different purposes (ten words illegible): and if, in several orders of vertebrata, we could trace origin (of) spinous processes and mon¬ strosities &c. we should say, instead of there existing a unity of type, morphology1, as we do when we trace the head as being the vertebrae metamorphosed. Be it observed that Naturalists, as they use terms of affinity without attaching real meaning, here also they are obliged to use meta¬ morphosis, without meaning that any parent of crustacean was really an animal with as many legs as crustacean has jaws. The theory of descent at once explains these wonderful facts. Now few of the physiologists who use this language really suppose that the parent of insect with the metamorphosed jaw, was an insect with [more] so many legs, or that the parent of flowering plants, originally had no stamens, or pistils or petals, but some other means of propagation,—and so in other cases. Now according to our theory during the infinite number of changes, we might expect that an organ used for a purpose might be used for a different one by his descendant, as must have been the case by our theory with the bat, porpoise, horse, &c., which are descended from one parent. And if it so chanced that traces of the former use and structure of the part should be retained, which is manifestly possible if not pro¬ bable, then we should have the organs, on which morphology is founded and which instead of being- metaphorical becomes plain and (and instead of being) utterly unintelligible becomes simple matter of fact2. 1 That is “ we should call it a morphological fact.” 2 In the Origin, Ed. i. p. 438, vi. p. 602, the author, referring to the expressions used by naturalists in regard to morphology and metamorphosis, says “ On my view these terms may be used literally.”](https://iiif.wellcomecollection.org/image/b31351761_0075.jp2/full/800%2C/0/default.jpg)
