1935: "Seeds from Space""Seeds from Space", a novelette by Laurence Manning; first published in Wonder Stories, June 1935Wonder Stories, June 1935, available at the Internet Archive; reprinted in Famous Science Fiction, Spring 1967Famous Science Fiction, Spring 1967, also available at the Internet Archive; perhaps the earliest story of an alien race (of intelligent trees in this case) in which each individual starts life with all of its ancestors' memories. From p. 16, a conversation between an earthman and a tree creature:
"The tree creatures looked at him a moment in sober silence. 'You did not even know what food trees live upon,' suggested the Babbler. You seem intelligent, but strangely uniformed.'
"'Ah, but I am not a botanist,' answered Blenkins. 'This is the age of specialization. One man knows only one subject.'
"'But your ancestors — some of them at least — must have known botany.'
"'What has that to do with me?'
"'You have, of course, all the knowledge and experience of your ancestors stored in your mind.'
"'Nonsense! Who ever heard of such a thing!' exclaimed Blenkins.
"'I do not understand. Did you not hear my words?'
"'I mean, what our ancestors knew has died with them.'
"'This is extraordinary! Do you have to learn all your facts over again each time a child is born?'
"'Why, of course! How else can anyone learn?'
"'Among us,' remarked Shorty quietly, 'we emerge from the seed with a precise memory of every thought that ever passed through the minds of our ancestors. I understand now, however, why you have so many books. It is to preserve the thoughts of one generation so that the next may learn them quickly.'