sensitiveness to conditions in 1841. All the varieties of the Dahlia are said to have arisen since 1804 (ibid. i. p. 393).
104
In the original MS. the heading is: Part III.; but Part II. is clearly intended; for details see the Introduction. I have not been able to discover where § IV. ends and § V. begins.
105
This passage corresponds roughly to the conclusion of the Origin, see Ed. i. p. 482, vi. p. 661.
106
A similar passage occurs in the conclusion of the Origin, Ed. i. p. 481, vi. p. 659.
107
See Origin, Ed. i. p. 312, vi. p. 453.
108
See Origin, Ed. i. pp. 280, 281, vi. p. 414. The author uses his experience of pigeons for examples for what he means by intermediate; the instance of the horse and tapir also occurs.
109
The absence of intermediate forms between living organisms (and also as regards fossils) is discussed in the Origin, Ed. i. pp. 279, 280, vi. p. 413. In the above discussion there is no evidence that the author felt this difficulty so strongly as it is expressed in the Origin, Ed. i. p. 299, – as perhaps “the most obvious and gravest objection that can be urged against my theory.” But in a rough summary written on the back of the penultimate page of the MS. he refers to the geological evidence: – “Evidence, as far as it does go, is favourable, exceedingly incomplete, – greatest difficulty on this theory. I am convinced not insuperable.” Buckland’s remarks are given in the Origin, Ed. i. p. 329, vi. p. 471.
110
That the evidence of geology, as far as it goes, is favourable to the theory of descent is claimed in the Origin, Ed. i. pp. 343-345, vi. pp. 490-492. For the reference to net in the following sentence, see Note 1, p. 48, {Link: Note 161} of this Essay.
111
See Origin, Ed. i. p. 288, vi. p. 422. “The remains that do become embedded, if in sand and gravel, will, when the beds are upraised, generally be dissolved by the percolation of rain-water.”
112
The position of the following is not clear: – “Think of immense differences in nature of European deposits, – without interposing new causes, – think of time required by present slow changes, to cause, on very same area, such diverse deposits, iron-sand, chalk, sand, coral, clay!”
113
The paragraph which ends here is difficult to interpret. In spite of obscurity it is easy to recognize the general resemblance to the discussion on the importance of subsidence given in the Origin, Ed. i. pp. 290 et seq., vi. pp. 422 et seq.
114
See Note 3, p. 27.
115
Compare Origin, Ed. i. p. 298, vi. p. 437. “We shall, perhaps, best perceive the improbability of our being enabled to connect species by numerous, fine, intermediate, fossil links, by asking ourselves whether, for instance, geologists at some future period will be able to prove that our different breeds of cattle, sheep, horses, and dogs have descended from a single stock or from several aboriginal stocks.”
116
The sudden appearance of groups of allied species in the lowest known fossiliferous strata is discussed in the Origin, Ed. i. p. 306, vi. p. 446. The gradual appearance in the later strata occurs in the Origin, Ed. i. p. 312, vi. p. 453.
117
Compare Origin, Ed. i. p. 307, vi. p. 448.
118
I have interpreted as Sandstone a scrawl which I first read as Sea; I have done so at the suggestion of Professor Judd, who points out that “footprints in the red sandstone were known at that time, and geologists were not then particular to distinguish between Amphibians and Reptiles.”
119
This refers to Cuvier's discovery of Palæotherium &c. at Montmartre.
120
This simile is more fully given in the Origin, Ed. i. p. 310, vi. p. 452. “For my part, following out Lyell’s metaphor, I look at the natural geological record, as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines. Each word of the slowly-changing language, in which the history is supposed to be written, being more or less different in the interrupted succession of chapters, may represent the apparently abruptly changed forms of life, entombed in our consecutive, but widely separated formations.” Professor Judd has been good enough to point out to me, that Darwin’s metaphor is founded on the comparison of geology to history in Ch. i. of the Principles of Geology, Ed. i. 1830, vol. i. pp. 1-4. Professor Judd has also called my attention to another passage, —Principles, Ed. i. 1833, vol. iii. p. 33, when Lyell imagines an historian examining “two buried cities at the foot of Vesuvius, immediately superimposed upon each other.” The historian would discover that the inhabitants of the lower town were Greeks while those of the upper one were Italians. But he would be wrong in supposing that there had been a sudden change from the Greek to the Italian language in Campania. I think it is clear that Darwin’s metaphor is partly taken from this passage. See for instance (in the above passage from the Origin) such phrases as “history … written in a changing dialect” – “apparently abruptly changed forms of life.” The passage within [] in the above paragraph: – “Lyell’s views as far as they go &c.,” no doubt refers, as Professor Judd points out, to Lyell not going so far as Darwin on the question of the imperfection of the geological record.
121
On rarity and extinction see Origin, Ed. i. pp. 109, 319, vi. pp. 133, 461.
122
In the Origin, Ed. i. p. 346, vi. p. 493, the author begins his discussion on geographical distribution by minimising the effect of physical conditions. He lays great stress on the effect of barriers, as in the present Essay.
123
Note in the original, “Would it be more striking if we took animals, take Rhinoceros, and study their habitats?”
124
Note by Mr A. R. Wallace. “The want of similarity referred to, is, between the mountains of Brazil and Guiana and those of the Andes. Also those of the Indian peninsula as compared with the Himalayas. In both cases there is continuous intervening land.
“The islands referred to were, no doubt, the Galapagos for dissimilarity from S. America; our own Islands as compared with Europe, and perhaps Java, for similarity with continental Asia.”
125
The arguments against multiple centres of creation are given in the Origin, Ed. i. p. 352, vi. p. 499.
126
In the Origin, Ed. i. p. 366, vi. p. 516, the author does not give his views on the distribution of alpine plants as original but refers to Edward Forbes’ work (Geolog. Survey Memoirs, 1846). In his autobiography, Darwin refers to this. “I was forestalled” he says, “in only one important point, which my vanity has always made me regret.” (Life and Letters, i. p. 88.)
127
«The following is written on the back of a page of the MS.» Discuss one or more centres of creation: allude strongly to facilities of dispersal and amount of geological change: allude to mountain-summits afterwards to be referred to. The distribution varies, as everyone knows, according to adaptation, explain going from N. to S. how we come to fresh groups of species in the same general region, but besides this we find difference, according to greatness of barriers, in greater proportion than can be well accounted for by adaptation. «On representive species see Origin, Ed. i. p. 349, vi. p. 496.» This very striking when we think of cattle of Pampas, plants «?» &c. &c. Then go into discussion; this
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