The glands of the skin develop as epidermal sprouts that invade the underlying mesoderm.

They generally develop from primitive hair follicles and retain these connections; the ducts deliver the secretion into the adult follicles from which it oozes onto the skin surface beside the projecting hairs. Two basic types, sweat and sebaceous glands (Fig. 10.7/9 and 10), are distinguished, but each occurs in various subvarieties and in more definitely specialized forms.