In his Natural and Moral History of the Indies, published in 1590, he proved himself honest and lucid.

Though entangled in most of the older scriptural views, he broke away from many; but the distribution of animals gave him great trouble.
Having shown the futility of St.Augustine's other explanations, he quaintly asks: "Who can imagine that in so long a voyage men woulde take the paines to carrie Foxes to Peru, especially that kinde they call 'Acias,' which is the filthiest I have seene?
Who woulde likewise say that they have carried Tygers and Lyons?
Truly it were a thing worthy the laughing at to thinke so.

It was sufficient, yea, very much, for men driven against their willes by tempest, in so long and unknowne a voyage, to escape with their owne lives, without busying themselves to carrie Woolves and Foxes, and to nourish them at sea." It was under the impression made by this new array of facts that in 1667 Abraham Milius published at Geneva his book on The Origin of Animals and the Migration of Peoples.

This book shows, like that of Acosta, the shock and strain to which the discovery of America subjected the received theological scheme of things.

It was issued with the special approbation of the Bishop of Salzburg, and it indicates the possibility that a solution of the whole trouble may be found in the text, "Let the earth bring forth the living creature after his kind." Milius goes on to show that the ancient philosophers agree with Moses, and that "the earth and the waters, and especially the heat of the sun and of the genial sky, together with that slimy and putrid quality which seems to be inherent in the soil, may furnish the origin for fishes, terrestrial animals, and birds." On the other hand, he is very severe against those who imagine that man can have had the same origin with animals.