Shiva's power (shakti) to act is embodied in his female consort Parvati. As the devoted wife of Shiva she is the idealization of feminine beauty and the embodiment of physical desire and spiritual grace. Parvati is the very expression of femininity, the woman par excellence, daughter of the Himalayas. She is beautiful, sweet, tender, and is always portrayed as Shiva's partner. The body has a quality known as prana, or inwardly held breath. This is identified as the essence of life. The gods and goddesses have their bodies tautly drawn, as if containing a pressure from within. She exists in various divine (both friendly and fearful) forms. Two of her fierce and very powerful forms are Durga (goddess beyond reach) and Kali (goddess of destruction). Both have eight hands and great power and energy (Shakti). Durga rides on a lion and Kali rides on a corpse of a demon. Parvati was called Sati in her previous divine incarnation. The family of Lord Shiva, Parvati and their sons Ganesha and Kartikeya is an ideal example of family unity and love. She has a charming personality. She is adored by married women for a happy married life. She is also called Mata or Mother, meaning Mother India and as such she is associated with fertility and the earth. She can be represented as the yoni, the female principle that surrounds the male linga. The power of a devi or a goddess is shakti. This Shakti is the activating energy. The female possesses this dynamic element or activating energy and is the creative force. Parvati and Uma are the beniegn aspects of the goddess as well as the destroyer goddesses Kali and Durga are in turn all aspects of the Devi, or the Great Goddess. Kali is the negative aspect of the Goddess and symbolizes death. In this form she is sometimes considered the presiding deity of famine and disease.