FAT, the name given to certain animal and vegetable products which are oily solids at ordinary temperatures, and are chemically distinguished as being the glyceryl esters of various fatty acids. (See the article OILS, FATS AND WAXES.) Fat is a normal con stituent of animal tissue, being found even before birth ; it occurs especially in the intra-muscular, the abdominal, and the subcutane ous connective tissues. In the vegetable kingdom fats especially occur in the seeds and fruits, and sometimes in the roots. Physio logical subjects concerned with the part played by fats in liv ing animals are treated in the articles, CONNECTIVE TISSUES;