1.The growth-promoting factor or factors for the blood and tissue flagellates studied are present in serum, but are not directly associated with albumin, euglobulin, pseudoglobulin or combinations of these three important fractions.
2.Neither hemoglobin nor washed erythrocytes contain the necessary stimulant.
3.This stimulant partially survives heating at 70°C. for 30 minutes, but is destroyed at 100°C.
4.The factor or factors are not para-aminobenzoic acid, pyridoxin, nicotinic acid, thiamin nor any other vitamins tested.
5.The essential stimulant is dialysable, and is probably lost during the process of fractionating the serum proteins.