All of the higher animals, such as the dog, horse, cat, ox, elephant, monkey, etc., possess this phase of memory.
Memory of Events (Education, Happenings, etc.).—The memory of events and their sequences is a faculty of the mind that is to be noticed in animals very low in the scale of life. In fact, psychical development is based almost wholly upon this mental attribute. The vast majority of what are now entirely instinctive habits were, in the beginning, the results of sensual perceptions formulated and remembered (consciously and unconsciously), which gave rise to conscious ideation; this conscious ideation, in turn, became instinct.
This part of my subject is treated at length in the chapter on [Reason], therefore I will only introduce here certain evidence of this phase of memory as it is to be observed in the lower animals, especially in insects. A wasp of the variety commonly called "mud-dauber" last summer built her nest on the ceiling of my room in one corner. The windows of this room remained open night and day during the hot summer months, so her nest was easy of access. One day, while the wasp was busy about her home, I closed all the windows and awaited developments. At length she flew toward a window, against which she landed with a thump which for a moment or two completely dazed her. The wasp soon discovered that she was barred from the outer world by some transparent, translucent substance; she then proceeded on a voyage of discovery, flying around the room and searching here and there and everywhere for an exit. She finally found a small hole in a window casing which communicated with the outside; through this she made her escape from the room. Upon opening the window I saw her examining the passage through which she had come, going through it repeatedly. She finally flew away, but shortly returned with a pellet of mud. Notwithstanding the fact that all the windows were then open, the wasp went at once to the hole in the casing, through which she made her way into the room and thence to her nest on the ceiling. She never again, so far as I was able to ascertain, made an exit or an entrance through the windows, but always made use of the hole in the casing. This little creature undoubtedly gave unmistakable evidences of ratiocination; she found that a transparent barrier had been placed in her way—a barrier so translucent and transparent that she could not see it until she actually felt it. She therefore concluded that she would never again risk injury by flying through the windows. What is most remarkable about this instance is that this insect derived her knowledge from a single experience, and at once profited thereby. The wasp remembered the event—her experience with the window glass—and avoided a like occurrence by going through the hole in the casing. Her experience was a bit of education.
There are many people alive to-day, probably, who saw the trained fleas which were on exhibition in the large cities of the United States some thirty or forty years ago. These little creatures had been taught to perform military evolutions, to dance, to draw miniature carts, to feign death, etc., at the command or signal of their owner and trainer. The mere fact that they possessed memory enough to learn, retain, and remember their lessons is not proof positive of reason, but the fact of their having restrained their natural tendency and desire to escape, when they could so easily gratify such a desire or tendency, is a potent factor in an argument for their possession of the ratiocinative faculty. Their teacher explained that he "brought them to reason" by keeping them at first in a glass vessel, where they jumped and bumped their heads to no purpose against the transparent walls of their prison. Thus their vaulting ambition was held in check, and they learned to reason from cause and effect.
It is a well-known fact that many of the higher animals can be taught to do many things entirely foreign to their natures. This is brought about entirely through the faculty of remembering events. I am confident that many of the lower animals, insects, crustaceans, reptiles, are likewise the possessors of this faculty, and are capable of being taught. I, myself, have succeeded in teaching a toad to hop over a stick at the word of command. Again, I taught two chameleons to take certain positions and to retain them at feeding time. These little creatures remembered their lesson, and at my whistle would "line up" on the particular book that I had designated as their dining-table. We have seen that fleas are capable of being highly educated, hence it is reasonable to presume that other insects, specially and generically akin to the flea, likewise possess the faculty of remembering events. Of course, this faculty is necessarily more highly developed in some animals than in others; it differs in degree of development, not in kind.
FOOTNOTES:
[35] Darwin, Descent of Man, pp. 262, 263.
[36] Huber, p. 172; quoted by Lubbock, Ants, Bees, and Wasps, p. 120; also by Kirby and Spence, Introduction to Entomology, Vol. III. p. 66; also by Newport, Trans. Ent. Soc., London, Vol. II. p. 239.
[37] Lubbock, Ants, Bees, and Wasps, p. 121 et seq.
[38] Lubbock, loc. cit. ante, p. 124.