Section 62. Similar From a Physiological Point of View, to the Secretory

glands which form the digestive fluids are those which furnish lubricating fluids, the lachrymal gland, and Harderian glands in the orbit internally to the eye, and posterior and anterior to it respectively, the sebaceous glands (oil glands) connected with the hair, and the anal and perineal glands. The secretions of excretory glands are removed from the body; chief among them are the sweat glands and kidneys. The sweat glands are microscopic tubular glands, terminating internally in a small coil (Figure VIII. s.g.) and are scattered thickly over the body, the water of their secretion being constantly removed by evaporation, and the small percentage of salt and urea remaining to accumulate as dirt, and the chief reasonable excuse for washing. The kidney structure is shown diagrammatically in Figure 5, Sheet 7. A great number of branching and straight looped, tubuli (little tubes) converge on an open space, the pelvis. Towards the outer layers (cortex) of the kidney, these tubuli terminate in little dilatations into which tangled knots of blood-vessels project: the dilatations are called Bowman's capsules (B.c.), and each coil of bloodvessel a glomerulus (gl.). In the capsules, water is drained from the blood; in the tubuli, urea and other salts in the urine are secreted from a branching network of vessels.