Registration begins at 10 a.m., August 17, for the fall session at Mt. Airy Learning Tree. Which offers educational and recreational classes three times a year in Northwest Philadelphia. Subjects range from mind and body (yoga, tai chi, qigong, singing bowls, foot reflexology.) to health and exercise (pilates, kickbox cardio boot camp, '80s aerobics, herbalism, acupressure, aromatherapy) to cooking, computers, arts and crafts, sports and recreation (horseback riding, row the Schuylkill, camping for women, tennis) and more.