From The Guardian:
In “The Book of Sand” (1975), Jorge Luis Borges describes a volume of inconceivably thin leaves in which no page is the first and no page the last, so that wherever you open it there is a different story, written in various indecipherable scripts. The narrator becomes obsessed with this extraordinary object and ultimately horrified: “I realised that the book was monstrous. It was no consolation to think that I … was no less monstrous than the book.” The short story echoes what is probably Borges's single most famous fiction, “The Library of Babel” (1941), which depicts a library of astronomical size containing everything that ever has been or could be written but in which meaning is elusive. The later work, however, written towards the end of the author's life, has a nightmarish quality that is less apparent in the earlier story.
Falling between these two is The Book of Imaginary Beings, a compendium of brief, almost stark descriptions and stories about fantastic animals from many older texts and sources, including the bestiaries of medieval Europe and their classical antecedents, Chinese and Indian myth, folk tales, the legends of indigenous peoples, and the minds of writers such as Kafka and Poe. First published in 1957, at the very time when (as Borges later explained) the vision that had gradually been failing him since birth had deteriorated to the point where he could no longer read or see what he was writing, this cryptozoological chiaroscuro is one of Borges's great creations. In the preface, Borges warns that Imaginary Beings is not meant to be read straight through: “Rather, we should like the reader to dip into these pages at random, just as one plays with the shifting patterns of a kaleidoscope.”