1. It is possible to fractionate gelatin by means of reprecipitation at 23 degrees C. of a salt-free solution of pH 4.7 into two fractions, one of which is soluble in water at any temperature, and a second one which does not dissolve in water even when heated to 80 degrees C. 2. The proportion of the soluble fraction in gelatin is much greater than of the insoluble one. 3. The insoluble fractio...

Light and electron microscopy were employed to examine ultrasonically irradiated murine neonate spinal cords. Spinal cord damage was always associated with functional changes, i.e. hind limb paralysis, and was never apparent in initially paralyzed specimens which had recovered function. Damage occurred preferentially at the periphery of the spinal cord and on the ventral side, though the ultras...