During attempts to induce xanthic lesions in the skin of animals it became necessary for us to review the literature pertaining to normal figures for animals and to check up on our own technic. Contemporary workers on blood cholesterol tell us that there is no one place where such data are brought together, and after a tedious search through a wide range of subjects in which the cholesterol phase played a greater or lesser part, we have come to the same conclusion. It is to obviate possible repetition of this work by subsequent workers that we report what we found. The values are recorded under the heading of the various technics which have been proposed. We trust that we have not overlooked many. Of the technic itself, only enough will be sketched in to indicate the principles concerned, or variations from other technics. Unless specially expressed in percentages, the values