The ebooks@cambridge team have just launched a trial to Very Short Introductions. There are 363 titles in the collection, which will be available until 31st December 2013. They are in subject areas in Arts and Humanities, Law, Medicine and Health, Science and Mathematics and Social Sciences. Titles in the Biological Sciences include: The Animal Kingdom, The Cell, The History of Life and Marine Biology.
For more information please see their blog post where there is a link to the trial itself.
Please let me have any feedback you have on this trial at firstname.lastname@example.org