Cambridge University on Wednessday has digitized Charles Darwin’s personal library and put all his annotations and notes in the margins online.

The digitization includes 330 of the most heavily annotated books already posted online for universal access, Geneanet website reported.

People can now easily search for a keyword within Darwin's annotations, rather than trawl through hundreds of thousands of pages for his relevant thoughts.

A press release by the University of Cambridge said that Darwin had over 1,480 books in his personal library, of which 730 comprehensive notes have scribbled notes in the margins.

The Darwin collections are among the most important and popular held within Cambridge University Library. While there has been much focus on his manuscripts and correspondence, his library hasn't always received the attention it deserves – for it is as he engaged with the ideas and theories of others that his own thinking evolved, university librarian Anne Jarvis said.

The release added that because Darwin’s evolutionary theory covered so many aspects of nature, reading served him as a primary source of evidence and ideas.

The majority of the books in Darwin’s personal library are scientific; some are humanities texts on subjects that Darwin transformed into scientific topics.

The British Library has announced a deal with Google in which about 250,000 copies published in the 18th and 19th centuries will go online.