His first notes on Galapagos finches appeared in “Narrative of the surveying voyages of His Majesty’s Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle’s circumnavigation of the globe. Journal and remarks. 1832–1836” , published in 1839 by Henry Colburn, London (spec. pp. 462 and 475; here is a link: http://darwin-online.org.uk/content/frameset?pageseq=472&itemID=F10.3&viewtype=side). There is another discussion in “On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life”, published in 1859 by John Murray, London (spec. pp. 398–399; http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F373&viewtype=side).

It wasn't really Darwin who described Darwin's finches. It was Gould:

@article{Gould:PZS-5-4,

title={Description of New Species of Finches Collected by {D}arwin

in the {G}alapagos},

author={Gould, J.},

journal={Proceedings of the Zoological Society of London},

volume=5,

pages={4--7},

year=1837

}

Hi Emilio. You can see the paper "Darwin and his finches: the evolution of a Legend" of Frank Sulloway. http://www.sulloway.org/Finches.pdf

Darwin wrote about these finches:

"The most curious fact is the perfect gradation in the size of the beaks in the different species of Geospiza, from one as large as that of a hawfinch to that of a chaffinch, and … even to that of a warbler…. Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends."

Darwin C. 1839 The voyage of the Beagle, Natural History Library (1962 edn.). Norwell, MA: Anchor Press, pp. 379-380.

Dear Emilio

Do consult Advanced Biology by Jones, M and Jones, G (1997), Cambridge University Press for insight. 

Our article published in peer-reviewed Journal "Communicative & Integrative Biology". A few major points discussed in the paper:

(1) Brain is not the source of consciousness.

(2) Consciousness is ubiquitous in all living organisms, starting from bacteria to human beings.

(3) The individual cells in the multicellular organisms are also individually cognitive entities.

(4) Proposals like “artificial life”, “artificial intelligence”, “sentient machines” and so on are only fairytales because no designer can produce an artifact with the properties like internal teleology (Naturzweck) and formative force (bildende Kraft).

(5) The material origin of life and objective evolution are only misconceptions that biologists must overcome.

http://www.tandfonline.com/doi/full/10.1080/19420889.2015.1085138

All 25 Books of Charles Darwin:

1839 late May

The three volume narrative of the Beagle voyage "Journal of Researches into the Natural History and Geology of the Countries Visited During the Voyage of H.M.S. Beagle" was published. This was the "three author" edition by Capt. Philip King, Capt. Robert FitzRoy, and Charles Darwin. Published by Henry Colburn Publishers of London. 

1839 August

Darwin's narrative of the Beagle voyage was published separately and given the title - "Journal of Researches into the Natural History and Geology of the Countries Visited During the Voyage of H.M.S. Beagle." Published by Henry Colburn Publishers of London. 

1839

Part-2 of Zoology of the Beagle Voyage - "Mammalia" written by George Waterhouse & published by Smith, Elder publishers of London. 

1840

Part-1 of Zoology of the Beagle Voyage - "Fossil Mammalia" wrtiien by Richard Owen & published by Smith, Elder publishers of London. 

1841

Part-3 of Zoology of the Beagle Voyage - "Birds" written by John Gould & published by Smith, Elder publishers of London. 

1842

Part-4 of Zoology of the Beagle Voyage - "Fish" written by Leonard Jeyns & published by Smith, Elder publishers of London. 

1842 May

Geological Observations of South America - "The Structure and Distribution of Coral Reefs." Published by Smith, Elder publishers of London. 

1843

Part-5 of Zoology of the Beagle Voyage - "Reptiles" written by Thomas Bell & published by Smith, Elder publishers of London. 

1844

Geological Observations of South America - "Volcanic Islands." Published by Smith, Elder publishers of London. 

1846

Geological Observations of South America - "South America" Published by Smith, Elder publishers of London. 

1851 (and 1854)

Two monographs on the sub-class of Barnacles, Cirripedia, were published. Each were of two volumes: "Living Cirripedia" and "Fossil Cirripedia" and published by the Ray Society of London. 

1851

"Monograph of the Fossil Lepadidae" was published by the Paleontological Society of England. 

1854

"Monograph of the Fossil Balanidae" was published by the Paleontological Society of England. 

1859 November 22

"The Origin of Species by Means of Natural Selection: Or, the Preservation of Favored Races in the Struggle for Life" was published by John Murray publishers of London. 

1862 May 15

"On the Various Contrivances by which British and Foreign Orchids and fertilized by Insects" was published John Murray publishers of London. 

1864 September 13

Darwin's 118 page treatise: "The Movement and Habits of Climbing Plants" was published by the Linnean Society. 

1868 January 30

"The Variations of Animals and Plants under Domestication" was published by John Murray publishers of London. 

1871 early March

"The Descent of Man and Selection in Relation to Sex" was published by John Murray publishers of London. 

1872 August

While on holiday at Leith Hill, Darwin finished the proofs for his book "The Expression of the Emotions in Man and Animals" was published by John Murray publishers of London. 

1875 July

"Insectivorous Plants" was published by John Murray publishers of London and sold faster and better than "Origin of Species". 

1876 Winter

"The Various Contrivances by which Orchids are Fertilized by Insects" and "The Effects of Cross and Self Fertilization in the Vegetable Kingdom" were both published by John Murray publishers of London. 

1877 July

"The Different Forms of Flowers on Plants of the Same Species" was published by John Murray publishers of London. 

1878 late Winter

The biography of his grandfather titled, "Erasmus Darwin" was published by John Murray publishers of London. 

1879 June

Darwin finished, "The Movement and Habits of Climbing Plants" and sent it to John Murray for publication. 

1881 October

"The Formation of Vegetable Mould, through the Actions of Worms, with Observations on Their Habits" was published by John Murray publishers of London.