Actually, the first name is the genus and the second name is the "specific epithet", which is an adjective describing the noun-genus, and thus can never stand alone. Its like tennis-ball or red ball... Ball is the genus and tennis (or red) describes what type of ball it is. So the species is the two word combination. The noun-adjective relationship is also why the generic term is always capitalized and the specific epithet is never capitalized.
