Humans have the conscious experience of 'free will': we feel we can generate our actions, and thus affect our environment. Here we used the perceived time of intentional actions and of their sensory consequences as a means to study consciousness of action. These perceived times were attracted together in conscious awareness, so that subjects perceived voluntary movements as occurring later and their sensory consequences as occurring earlier than they actually did. Comparable involuntary movements caused by magnetic brain stimulation reversed this attraction effect. We conclude that the CNS applies a specific neural mechanism to produce intentional binding of actions and their effects in conscious awareness.

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Proteins and colloidal materials, administered orally to suckling rats and mice, were ingested by columnar absorptive cells of the jejunum and ileum, but not of the duodenum. Bovine gamma globulin and ovalbumin were identified in the apical cytoplasm by staining with fluorescent antibody; trypan blue, Evans blue, saccharated iron oxide, and colloidal gold were detected intraceliularly by their color, specific staining, and appearance in the electron microscope. Each substance was segregated in membrane-enclosed vacuoles, apparently part of a system of potentially interconnecting vacuoles and tubules in the apical cytoplasm which is continuous in places with the apical cell membrane. We postulate that ingestion of foreign materials was accomplished by pinocytosis, that is, by invagination of the apical cell membrane to form vacuoles containing materiaJ from the intestinal lumen.

Renal structure and function are incompletely developed at birth in a number of mammals, including the rat and man. Functional immaturity manifests itself as an inability on the part of the kidney to vary the volume and concentration of the urine (McCance, 1948). I n the rat, renal function matures during the first few weeks after birth (Falk, 1955). Detailed studies of the structural changes in kidneys of newborn animals have been confined largely to the rat.During the first few weeks after birth, the rat kidney grows as a result of the formation of new nephrons in the peripheral zone of the cortex (Kittelson, 1917;Arataki, 1926), and at the same time the cells of the kidney acquire their specific cytological characteristics. Stergios, in an unpublished thesis (1933), has described the development of the brush border in the proximal tubules and the formation of basal striations, the Stabchen of Heidenhain (1874), in proximal and distal tubules. At birth the proximal tubules possess a homogeneous cuticular border which acquires the appearance of a brush border during the first 2 weeks after birth. The basal striations develop during this time by a process of alignment of the mitochondria, which were randomly arranged at birth, into rows perpendicular to the basement membrane. Between 4 and 9 days after birth, the brush border and basal striations achieve a state of organization which renders them birefringent (Olivecrona and Hillarp, 1949). Coincident with the development of the brush border, the cells of the proximal tubules acquire the ability to stain intravitally with trypan blue (Baxter and Yoffey, 1948). The alkaline phosphatase reaction and the periodic acid-Schiff staining properties of the brush border continue to differentiate for several months after birth in the mouse (Longley and Fisher, 1956) Cytoplasmic droplets that stain with the periodic acid-Schiff technique occur in the proximal tubules of a variety of mammalian fetuses, including the rat and man (Davies, 1954). Their presence is associated with proteinuria, and both droplets and proteinuria disappear soon after birth in most animals. Similar droplets have been produced in the proximal tubules of adult rats by the administration of certain

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