Abstract
(1) SYMPTOMS of meningeal irritation may precede or accompany the appearance of the serum rash. (2) Though serum disease is frequent after intrathecal injection of serum, especially after Flexner's antimeningitis serum, it is not clear that it is more frequent than after hypodermic injection of serum. (3) Intrathecal injection of serum necessarily involves risk of inducing increased intracranial pressure and may introduce a secondary infection; but it is not proved that the volume of serum injection favours a secondary infection of the meninges from the blood stream.