Again, it should not rouse astonishment that so remarkable and delicately organized a function as memory should be subject to anomalies and abnormalities of all kinds. We must take it as a rule not to assume the impossibility of the extraordinary phenomena that appear and to consult the expert about them.[227] The physician will explain the pathological and pathoformic, but there is a series of memory-forms which do not appear to be diseased, yet which are significantly rare and hence appear improbable. Such forms will require the examination of an experienced expert psychologist who, even when unable to explain the particular case, will still be able to throw some light on it from the literature of the subject. This literature is rich in examples of the same thing; they have been eagerly collected and scientifically studied in the earlier psychological investigations. Modern psychology, unfortunately, does not study these problems, and in any event, its task is so enormous that the practical problems of memory in the daily life must be set aside for a later time. We have to cite only a few cases handled in literature. The best known is the story of an Irish servant girl, who, during fever, recited Hebrew sentences which she had heard from a preacher when a child. Another case tells of a very great fool who, during fever, repeated prolonged conversations with his master, so that the latter decided to make him his secretary. But when the servant got well he became as foolish as ever. The criminalist who has the opportunity of examining deeply wounded, feverish persons, makes similar, though not such remarkable observations. These people give him the impression of being quite intelligent persons who tell their stories accurately and correctly. Later on, after they are cured, one gets a different opinion of their intelligence. Still more frequently one observes that these feverish, wounded victims know more, and know more correctly about the crime than they are able to tell after they have recovered. What they tell, moreover, is quite reliable, provided, of course, they are not delirious or crazy. The cases are innumerable in which people have lost their memory for a short time, or for ever. I have already elsewhere mentioned an event which happened to a friend of mine who received a sudden blow on the head while in the mountains and completely lost all memory of what had occurred a few minutes before the blow. After this citation I got a number of letters from my colleagues who had dealt with similar cases. I infer, therefore, that the instances in which people lose their memory of what has occurred before the event by way of a blow on the head, are numerous.[228]