Note 122 — Chapter X

Philosophical Discussions, p. 256. See also Animal Intelligence, pp. 269, 270, for the case of a parrot apparently endeavouring to recover the memory of a particular word in a phrase. In the course of an interesting research on the intelligence of spiders (Journ. Morphol., i., p. 383-419), Mr. and Mrs. Peckham have recently found that the memory of eggs which have been withdrawn from the mother is retained by her for a period varying in different species from less than one to more than two days.