[{319}] Origin, Ed. i. pp. 288, 300, vi. pp. 422, 438.
[{320}] «Note in original.» Neither highest or lowest fish (i.e. Myxina «?» or Lepidosiren) could be preserved in intelligible condition in fossils.
[{321}] Origin, Ed. i. p. 290, vi. p. 425.
[{322}] See Origin, Ed. i. p. 310, vi. p. 452 for Lyell's metaphor. I am indebted to Prof. Judd for pointing out that Darwin’s version of the metaphor is founded on the first edition of Lyell’s Principles, vol. I. and vol. III.; see the Essay of 1842, p. 27.
[{323}] See More Letters, vol. I. pp. 344-7, for Darwin’s interest in the celebrated observations of Hilgendorf and Hyatt.
[{324}] This corresponds partly to Origin, Ed. i. p. 294, vi. p. 431.
[{325}] Origin, Ed. i. p. 299, vi. p. 437.
[{326}] This chapter corresponds to ch. X of Origin, Ed. i., vi. ch. XI, “On the geological succession of organic beings.”
[{327}] Origin, Ed. i. p. 312, vi. p. 453.
[{328}] In the margin the author has written “Lonsdale.” This refers to W. Lonsdale’s paper “Notes on the age of the Limestone of South Devonshire,” Geolog. Soc. Trans., Series 2, vol. V. 1840, p. 721. According to Mr H. B. Woodward (History of the Geological Society of London, 1907, p. 107) “Lonsdale’s ‘important and original suggestion of the existence of an intermediary type of Palæozoic fossils, since called Devonian,’ led to a change which was then ‘the greatest ever made at one time in the classification of our English formations’.” Mr Woodward’s quotations are from Murchison and Buckland.