He takes on the problems of Pangenesis to boot, 2,100 years before Darwin adopted it as his theory of heredity.
On the Generation of Animals, 722b:
Again, if the semen come from all parts of both parents alike, the result is two animals, for the offspring will have all the parts of both. Wherefore Empedocles seems to say what agrees pretty well with this view (if we are to adopt it), to a certain extent at any rate, but to be wrong if we think otherwise. What he says agrees with it when he declares that there is a sort of tally in the male and female, and that the whole offspring does not come from either, ‘but sundered in the fashion of limbs, some in man’s…’ For why does not the female generate from herself if the semen comes from all parts alike and she has a receptacle ready in the uterus? But, it seems, either it does not come from all the parts, or if it does it is in the way Empedocles says, not the same parts coming from each parent, which is why they need intercourse with each other.
Yet this is impossible…
– Translation by Arthur Platt, from The Basic Works of Aristotle, Richard McKeon, ed., Modern Library (1941).
The Finch and Pea 