BIRDS — MEMORY. 267 
meet with satisfactory evidence of the memory of a bird 
enduring for a longer time than this. 
As it is a matter of interest in comparative psychology 
to trace as far as possible into detail the similarities of a 
mental faculty as it occurs in different groups of animals, and 
as the faculty of memory first admits of detailed study in 
the class which we are now considering, I shall here devote 
a paragraph to the facts concerning the exhibition of 
memory by birds where its mechanism best admits of being 
analysed ; I refer to the learning of articulate phrases and 
tunes by talking and musical birds. The best observa- 
tions in this connection with which I am acquainted are 
those of Dr. Samuel Wilks, F.K.S., and therefore I shall 
quote in extenso the portion of his paper which refers to 
the memory of parrots : other portions of this paper I 
shall have occasion to quote in my next work : — 
When my parrot first came into my possession, several years 
ago, it was quite unlettered, and I therefore had an opportunity 
of observing the mode in which it acquired the accomplishment 
of speech. I was very much struck with its manner of learn- 
ing, and the causes for its speaking on special occasions. The 
first seemed to resemble very much the method of children in 
learning their lessons, and the second to be due to some associa- 
tion or suggestion — the usual provocative for set speeches at all 
periods of human life. A parrot is well known to imitate 
sounds in a most perfect manner, even to the tone of the voice, 
besides having a compass which no human being can approach, 
ranging from the gravest to the most acute note. My bird, 
though possessing a good vocabulary of words and sentences, 
can only retain them for a few months unless kept constantly in 
practice by the suggestive recurrence of some circumstance 
which causes their continual utterance. If forgotten, however, 
they are soon revived in the memory by again repeating them 
a few times, and much more speedily than any new sentence can 
be acquired. In beginning to teach the parrot a sentence, it has 
to be repeated many times, the bird all the while listening most 
attentively by turning the opening of the ear as close as pos- 
sible to the speaker. After a few hours it is heard attempting 
liberty, cautiously eluded all his attempts : and suddenly glancing his 
eye on his distant companions, mounted in the air after them, soon 
overtook and mingled with them, and was never afterwards seen to 
return.’ 
