De acordo com um comentário do OP, a primeira das histórias listadas aqui que satisfaz seus critérios é "Sanguessugas cerebrais" de Histórias AstoundingJulho 1935. Se você tiver um antes de julho, 1935, poste uma resposta. As histórias rejeitadas pelo OP são indicadas com um ponto de interrogação.
1955: "Por um Fluke" by Arthur Porges. Pensamentos de um acaso inteligente do fígado.
1950 (?): "Êxodo estranho" by Robert Abernathy; publicado pela primeira vez em Planet Stories, Queda 1950, disponível no Internet Archive. Os seres humanos viajam para as estrelas como parasitas em gigantescos vermes espaciais.
1939: "Discórdia em escarlate" by AE van Vogt, proposto em Resposta de Ram; publicado pela primeira vez em Ficção Científica EspantosaDezembro 1939, disponível no Internet Archive. Incorporado no romance de correção 1950 de van Vogt A viagem do espaço Beagle que tem um Wikipedia página.
1936: "Os pigmeus de Fobos" by Ralph Robin. De EF Bleilerrevisão de Ficção científica: Os anos Gernsback:
Ages ago, two forms of intelligent life arose on Mars, humanoid creatures much like mankind and protozoa about a millimeter across. Both peoples developed mechanical civilizations at about the same time. When they became aware of each other, however, they immediately began wars of extermination. [. . .] Finally, after thousands of years of war, the peoples made a shaky peace. The protozoans, fearful that war would break out again, made a suggestion that satisfied both races: encasing Phobos in a shell to retain necessities of life and leaving the protozoans there, leaving Mars to the humans. [. . .] At this point, the protozoan dictator Thakin proposed an invasion of Mars. The council rejected this proposal with horror, but Thakin, gathering his followers and seizing the entire planetary supply of thorium, fled to Mars. There, he inserted individual protozoa into the brains of Martians, subjecting them to protozoan control.
[Este definitivamente conta: parasitas cerebrais macroscópicos.]
1935 (?): "Planeta parasita" by Stanley G. Weinbaum, descrito em estas perguntas e respostas; tem um Wikipedia página e está disponível em Projeto Gutenberg Austrália. [Por um comentário do OP, fungos não contam.]
1935: "Sanguessugas cerebrais" by Edward S. Mund; publicado pela primeira vez em Histórias AstoundingJulho 1935, disponível no Internet Archive. De EF Bleilerrevisão de Ficção científica: Os anos Gernsback:
The beings on the spaceship close in the immediate area with a force screen of sorts and herd in the two young men. Near the spaceship, Jack encounters humans, and learns from them that the aliens are amoeboid puppet-masters who use humans as carriers. As Jack learns from a captive young woman from another planet, who either speaks English or is a telepathic broadcaster, the monsters, who are few in number, control their "steeds" by inserting tentacles up into their brains. Jack also learns from the monsters, one of whom rides him, that they plan to spawn and take over the Earth.
[Eu acho que este conta. Não está completamente claro a partir da revisão, mas os alienígenas parecem ser macroscópicos ("amebóides"), e se eles não estão vivendo dentro ou permanentemente presos aos seus "corcéis", pelo menos eles têm seus tentáculos embutidos no cérebro do corcel].
1933 (?): "O cérebro roxo" by Hal K. Wells; publicado pela primeira vez em Histórias AstoundingDezembro 1933, disponível no Internet Archive. De EF Bleilerrevisão de Ficção científica: Os anos Gernsback:
Neil Andrews and John Kincaid, while out horseback riding in the hills, encounter a cougar that has something on its head—a purplish, lumninescent jelly-like object that emits a feeling of overwhelming horror and cosmic evil. Kincaid shoots at the cougar, whereupon it springs away, while the two men are thrown from their panic-stricken horses. * Kincaid is not altogether ignorant of the monster, for he has heard tales according to which it is associated with the lodge occupied by the scientist Yaagir. * On proceeding to Yaagir's place, they are captured by the strange being, which now occupies a monstrous cadaver formed by combining two human bodies. The creature explains: Arriving from the planet Zaas, which is about six light-years away, it is a scout investigating the Earth and mankind. It will report back to Zaas, whereupon a huge fleet will come to Earth and conquer it, enslaving mankind as carriers for the jelly beings. As the two men can see from corpses lying about, the creature removes the top of the cranium, then infiltrates the brain. While the men watch in horror, the jelly being vivisects a couple of other captives, using a cosmic ray apparatus that both removes tissue and records the results photographically. [. . .] Not one of Wells's better stories, but perhaps the earliest instance of the puppet-master motif.
[Eu acho este não conta. Aparentemente, a geléia só habita cadáveres, portanto não é um parasita.]
1930 (?): Últimos e Primeiros Homens by Olaf Stapledon tem um Wikipedia página e está disponível em Projeto Gutenberg Austrália. Os invasores marcianos de Stapledon são nuvens de unidades ultramicroscópicas que se comunicam telepaticamente para formar um "mente de grupo", um termo aparentemente cunhado por Stapledon. Nos quintos homens, as unidades marcianas se tornaram parasitas, conferindo capacidade telepática:
In sensory equipment, the new man was to have all the advantages of the Second and Third Men, and, in addition, a still wider range and finer discrimination in every sense organ. More important was the incorporation of Martian units in the new model of germ cell. As the organism developed, these should propagate themselves and congregate in the cells of the brain, so that every brain area might be sensitive to ethereal vibrations, and the whole might emit a strong system of radiation. But care was taken that this "telepathic" faculty of the new species should remain subordinate. There must be no danger that the individual should become a mere resonator of the herd.
[Este exemplo provavelmente não conta. Os marcianos de vida livre originais que invadiram a Terra tinham mentes de colméia, mas como parasitas eles podem ter sido irracionais.]
1923 (?): "Ilha dos fungos" by Philip M. Fisher Jr., descrito em este velho Q & A; publicado pela primeira vez em Argosy All-Story Weekly, Outubro 27, 1923; reimpresso em Mistérios Fantásticos Famosos, Outubro 1940, que está disponível no Internet Archive. [Por um comentário do OP, fungos não contam.]
1907 (?): "A voz na noite" by William Hope Hodgson, também descrito em as mesmas perguntas e respostas antigas, está disponível em Projeto Gutenberg Austrália e Librivox. De EF Bleilerrevisão de Ficção científica: Os primeiros anos:
Somewhere in the North Pacific, the narrator who is fogbound on a
small vessel, is hailed by an unseen man in a rowboat. The
circumstances are suspicious, particularly when the stranger, who asks
for food, will not come close to the ship and insists that the lights
be extinguished. But the compassionate sailors float a box of supplies
to him. Some time later the invisible rower returns and tells his
story from out of the fog. Victims of a shipwreck, he and his fiancee
have been living on a nearby island that is covered with fungi. The
fungus is not only omnipresent, but some examples are shaped like
trees and humans. The narrator and his fiancee tried to avoid the
fungus, but after a time observed that it was sprouting on them. There
was nothing they could do, for even carbolic acid would not kill it.
When their food was nearly gone, they yielded to temptation and began
to eat the fungus, though with strong feelings of guilt. They do not
expect to live long. As the stranger moves away, the fog lifts for a
moment, and the sailors see what seems to be a blob-shaped fungus in
the rowboat.
[Por um comentário do OP, fungos não contam.]
