The Description of a New World, Called the Blazing-World

They answered, That, as much as they could perceive, some had Blood, and some not; a Moth, said they, had no Blood at all, and a Lowse had, but like a Lobster, a little Vein along her back: Also Nits, Snails, and Maggots, as well as those that are generated out of Cheese and Fruits, as those that are produced out of Flesh, had no blood: But, replied the Empress, If those mentioned creatures have no blood, how is it possible they can live? for it is commonly said, That the life of an Animal consists in the blood, which is the seat of the Animal spirits. They answered, That blood was not a necessary propriety to the life of an Animal; and that that which was commonly called Animal spirits, was nothing else but corporeal motions proper to the nature and figure of an Animal. Then she asked both the Fish- and Worm-men, whether all those Creatures that have blood, had a circulation of blood in their veins and arteries? But they answered, That it was impossible to give her Majesty an exact account thereof, by reason the circulation of blood was an interior motion, which their senses, neither of themselves, nor by the help of any Optick Instrument could perceive; but as soon as they had dissected an Animal Creature, to find out the truth thereof, the interior corporeal motions proper to that particular figure or creature, were altered.