The modern psychologists, by the science which they call comparative psychology, have gradually been robbing humanity of much that it used to plume itself upon as its own unique possession. Among the last strongholds to yield were reason and language, and the defenders of these, although retreating, are hardly yet put to rout. Even if the articulate speech of the parrot and the jackdaw is only “imitation”, and the alleged language of the apes a delusion, still it is something of an open question whether the sounds and gestures which animals use with one another are not really of the nature of language. The fox who doubles on his track in order to lead the dogs on a false scent is getting very close to language in a rudimentary sense, and the dog who sits up or barks for food or wags his tail to express good will, perhaps nearer still. It is a long step, however, from even developed oral and gesture language to record, and it is still generally denied that among the traits of our kinship with the beasts any evidence has been discovered of what can be called record keeping. If this were true, then it would seem to follow that the animal ceased to be animal and became man precisely when he invented and began to practice record keeping—in short that libraries mark the very beginning of the human race! On the other hand, however, it cannot be ignored that the psychologists are publishing monographs on the arithmetic of animals and the memory for facts among animals, and scores of other monographs on the minds of animals. There are those too who claim that the dog even marks the place where he caches his surplus of bones, and certainly the bringing home of a dead woodchuck, in order to show his master what he has done, comes very close to that keeping and exhibiting of human trophies which is recognized as among the beginnings of “handwriting”. If it is true that the animals do make conscious marks to guide them back to hidden objects, or even that they do have memory for facts, which is true memory, then possibly the beginnings at least of memory libraries and perhaps of external records must in the future be sought in the animal world. The ancient Egyptians, of course, found it there when they made the writing ape author, owner, and keeper of books. Perhaps after six thousand years modern psychology is about to catch up with this idea! Whether or not future psychology discovers anything like actual record collections and memory libraries among the animals, it remains true that the study of comparative psychology does lead into the beginnings of memory and helps therefore to the study of the real nature of human memory-books and memory libraries, while again it leads into the question of the nature of gesture language, and gesture is the own father of hand-written books. When true libraries have been discovered among animals it will be time enough to take up the question of plant libraries.