The key to the genital apparatus in women from the psychic point of view, and, indeed, to some extent, its anatomical center, is to be found in the clitoris. Anatomically and developmentally the clitoris is the rudimentary analogue of the masculine penis. Functionally, however, its scope is very much smaller. While the penis both receives and imparts specific voluptuous sensations, and is at the same time both the intromittent organ for the semen and the conduit for the urine, the sole function of the clitoris is to enter into erection under the stress of sexual emotion and receive and transmit the stimulatory voluptuous sensations imparted to it by friction with the masculine genital apparatus. It is so insignificant an organ that it is only within recent times that its homology with the penis has been realized. In 1844 Kobelt wrote in his important book, _Die Mannlichen und Weiblichen Wollust-Organe_, that in his attempt to show that the female organs are exactly analogous to the male the reader will probably be unable to follow him, while even Johannes Müller, the father of scientific physiology, declared at about the same period that the clitoris is essentially different from the penis. It is indeed but three centuries since the clitoris was so little known that (in 1593) Realdus Columbus actually claimed the honor of discovering it. Columbus was not its discoverer, for Fallopius speedily showed that Avicenna and Albucasis had referred to it.[85] The Arabs appear to have been very familiar with it, and, from the various names they gave it, clearly understood the important part it plays in generating voluptuous emotion.[86] But it was known in classic antiquity; the Greeks called it myrton, the myrtle-berry; Galen and Soranus called it nymphê because it is covered as a bride is veiled, while the old Latin name was _tentigo_, from its power of entering into erection, and _columella_, the little pillar, from its shape. The modern term, which is Greek and refers to the sensitiveness of the part to voluptuous titillation, is said to have originated with Suidas and Pollux.[87] It was mentioned, though not adopted, by Rufus. "The clitoris," declared Haller, "is a part extremely sensible and wonderfully prurient." It is certainly the chief though by no means the only point through which the immediate call to detumescence is conveyed to the female organism. It is, indeed, as Bryan Robinson remarks, "a veritable electrical bell button which, being pressed or irritated, rings up the whole nervous system."