瑜伽論記 1.510

1.510

化生中，或具不具六種者，不具謂無想天無第六意處及一切生有死有。或云劫初鬼畜，未必具根，而化生故。

Regarding "either complete or incomplete with respect to the six kinds" among the apparitionally born: "incomplete" refers to the heaven without conception lacking the sixth mental sense-base, as well as all intermediate states of birth and death. Or it is said that at the beginning of the eon, ghosts and animals did not necessarily have all their sense faculties complete, yet they were apparitionally born.