Using a sensitive photo electric spectrophotometer, carotene derived from carrots and dissolved in an oil, has been found to exhibit an absorption band in the region 325-330 Mμ. An absorption band in this region has been shown by Morton & Heilbron to be characteristic of vitamin A in fats derived from animal sources. The appearance of this band in carotene from a vegetable source, establishes an even closer relationship between these two growth-promoting factors
