Fat tissue is a special form ofconnective tissue, one in which some ofthe cells take on the role of storing energy.Animals form fat tissue in three differentparts of the body: just under the skin,where it can provide insulation as well asenergy; in well-defined deposits in the bodycavity, often around the kidneys, intestine,and heart; and in the connective tissue sep-arating muscles and the bundles withinmuscles. The term “marbling” is used todescribe the pattern of white splotches inthe red matrix of muscle.