The facts presented suggest strongly that reticulo-endothelial cells are actively concerned in the formation of amyloid. Points in favor of this theory are as follows:
1. The appearance of amyloid in places where reticulo-endothelial cells are normally present, sometimes in very large number.
2. The formation of early amyloid in the small solitary patches, which suggests its local formation.
3. The occurrence of solitary patches of amyloid apparently located within the capillaries of the liver.
4. The manifold relations between reticulo-endothelial cells marked out by phagocytized ink granules, loose ink particles and amyloid, described in the text.
5. The impossibility of demonstrating reticulo-endothelial cells in areas of forming amyloid by intravenous injections of India ink.
6. The delayed appearance of amyloid in animals after blockage of the reticulo-endothelial cells by repeated intravenous injections of India ink.