A survey on the present status of bovine β-crystallin is given. The designation βHigh and βLow is proposed for the two β-fractions separable by gel filtration. Both fractions consist of several polypeptides and share the major polypeptide chain. This chain has been purified and partly characterized. Its molecular weight is approximately 27,000 dalton. Serine has been found as C-terminal amino acid. In theelectron microscope, βLappears as small globular particles.