Notebook written from both ends, with text running in opposite directions inward from each cover, inverted with respect to each other. In this transcript, the pages of the back section have been arranged in reverse order and placed after the pages of the front section. The front section has notes on a variety of subjects, including accounts of collecting insects and orangutans in Sarawak, and notes for a book about evolution that he was planning to write (see Costa, 2013). He abandoned his work on it after learning that Charles Darwin was working on a book on the same subject. The back section of the notebook has notes about insects, and tallies of the numbers of species he collected in various places. This notebook differs from his other three field notebooks in that it does not contain any numbered lists of the individual species of a group that he collected in an island or region. Note that this notebook is popularly known as his "Species Notebook", but this title is inappropriate given that only a small proportion of it is devoted ARW's musings about the evolution of species. Original in Linnean Society of London: MS/180 (images: https://linnean.access.preservica.com/uncategorized/IO_6c29cbb1-06be-4b69-a4e4-0fc7079ae2ef/). This transcript was produced by James and Leslie Costa, and first published in Costa, J. T. (Ed.). 2013. On the Organic Law of Change: A Facsimile Edition and Annotated Transcription of Alfred Russel Wallace's Species Notebook of 1855-1859. Cambridge MA: Harvard University Press. Minor corrections have been made by the A. R. Wallace Correspondence Project (https://wallaceletters.myspecies.info/). Text © Alfred Russel Wallace Literary Estate