When Hans suddenly became a celebrity, and he, himself, the object of an enthusiastic following, the whole affair evidently took Mr. von Osten off his feet. Strangers took the further instruction of the horse in charge, and the rate and degree of Hans's progress became disconcerting. One day it came to pass that the horse even understood French, and the old gentleman, whose apostolic exterior had always exerted a high degree of suggestion upon his admirers, in turn fell captive to the spell of retroactive mass-suggestion. He no longer was uneasy concerning the most glaring kinds of failure. On one occasion he even insisted upon the completion of a series of tests in which procedure was "without knowledge", which promised no results whatever. "The animal's stubbornness must be broken," he commented. On the other hand, he regarded every criticism as a form of personal insult. And once he showed a member of the committee of the Society for the Protection of Animals the door, because the man, without having looked at his watch, wanted to show it to Hans and ask him the time. Many other critics had similar experiences. Summarizing the remarks of this chapter, our judgment must be as follows: It is in the highest degree improbable that Mr. von Osten purposely trained the horse to respond to certain cues. It is also improbable that he knew that in every test he was giving signals, (although I can form no judgment concerning what happened after the publication of the latest report). To assume the contrary would land us in the midst of insoluble contradictions of the many ascertained facts in the case. The explanation here essayed, however, should prevent that. To be sure, we, must then reckon with curious inner contradictions in Mr. von Osten's character. But such contradictions are to be found, upon earnest analysis, in nearly every human character. And Mr. von Osten may say with the poet: "Ich bin kein ausgekluegelt Buch. Ich bin ein Mensch mit seinem Widerspruch." CONCLUSION If we would make a brief summary of the status of Mr. von Osten's horse in the light of these investigations and try to understand what is the bearing upon the question of animal psychology in general, we may make the following statements. Hans's accomplishments are founded first upon a one-sided development of the power of perceiving the slightest movements of the questioner, secondly upon the intense and continued, but equally one-sided, power of attention, and lastly upon a rather limited memory, by means of which the animal is able to associate perceptions of movement with a small number of movements of its own which have become thoroughly habitual. The horse's ability to perceive movements greatly exceeds that of the average man. This superiority is probably due to a different constitution of the retina, and perhaps also of the brain. Only a diminishingly small number of auditory stimuli are involved.