In order to explain dispersal of food from alimentary canal _viâ_ the veins (_anadosis_) there is no need to invoke with Erasistratus, the _horror vacui_, since here again the principle of specific attraction is operative; moreover, blood is also driven forward by the compressing action of the stomach and the contractions of the veins. Possibility, however, of Erasistratus's factor playing a certain minor _rôle_. Chapter II The Erasistratean idea that bile becomes separated out from the blood in the liver because, being the thinner fluid, it alone can enter the narrow stomata of the bile-ducts, while the thicker blood can only enter the wider mouths of the hepatic venules. Chapter III The morphological factors suggested by Erasistratus are quite inadequate to explain biological happenings. Erasistratus inconsistent with his own statements. The immanence of the _physis_ or nature; her shaping is not merely external like that of a statuary, but involves the entire substance. In genesis (embryogeny) the semen is the active, and the menstrual blood the passive, principle. Attractive, alterative, and formative faculties of the semen. Embryogeny is naturally followed by growth; these two functions distinguished. Chapter IV Unjustified claim by Erasistrateans that their founder had associations with the Peripatetic (Aristotelian) school. The characteristic physiological tenets of that school (which were all anticipated by Hippocrates) in no way agree with those of Erasistratus, save that both recognize the purposefulness of Nature; in practice, however, Erasistratus assumed numerous exceptions to this principle. Difficulty of understanding why he rejected the biological principle of attraction in favour of anatomical factors. Chapter V A further difficulty raised by Erasistratus's statement regarding secretion of bile in the liver. Chapter VI