I shall describe briefly the reaction produced in two general paralytic brains by punctures with sterile needles for the purpose of introducing arsphenaminized serum into the ventricles.
Pfeiffer,1 studying puncture canals produced by sterile blunt needles, in an effort to locate brain tumors, stated that inflammatory reaction of the glia was never present, but that cicatrization was accomplished through pure connective tissue proliferation without the aid of glia. Tschistowitsch,2 after studying the brains of dogs and pigeons from three to one hundred and thirty days after injury with a platinum needle, concluded that connective tissue elements of the pia and vessels play the chief rôles in the healing process; and that the part played by the neuroglia is insignificant, merely aiding in the formation of a sclerotic zone about the cicatrix by shrinking. In the brains of dogs receiving needle punctures, Penfield3 after six days found fibroblasts