Regarding these names it may be said that the former has not yet been satisfactorily interpreted. On the assumption that the union of the syllables A-nun-na-ki[216] represents a compound ideograph, the middle syllable _nun_ signifies 'strength,' whereas the first is the ordinary ideograph for 'water.' Hommel[217] proposed to interpret the name therefore as 'gods of the watery habitation.' The artificiality of this manner of writing points, as in several instances noted, to a mere 'play' upon the real name. _Anunna_ reminds one forcibly of the god _Anu_ and of the goddess _Anunit_, and the element _ak_ is quite a common afformative in Babylonian substantives, conveying a certain emphatic meaning to the word. If therefore we may compare Anun with the name of the god of heaven, the name _Anunnak_ embodying, as it does in this case, the idea of power, would be an appropriate designation for the spirits, or a group of spirits collectively. Be it understood that this explanation is offered merely as a conjecture, which, however, finds support in the meaning attached to the term 'Igigi.' This, as Halevy and Guyard have recognized, is a formation of a well-known stem occurring in Babylonian, as well as in other Semitic languages, that has the meaning 'strong.' The ideographic form of writing the name likewise designates the spirits as 'the great chiefs.' The 'Igigi,' therefore, are 'the strong ones,' and strength being the attribute most commonly assigned to the Semitic deities,[218] there is a presumption, at least, in favor of interpreting Anunnak, or Anunnaki,[219] in the same way. The 'Igigi' are at times designated as the seven gods, but this number is simply an indication of their constituting a large group. Seven is a round number which marked a large quantity. At an earlier period five represented a numerical magnitude, and hence the Anunnaki are at times regarded as a group of five.[220] The Anunnaki and Igigi appear for the first time in an historical text in the inscription of the Assyrian king Ramman-nirari I., who includes them in his appeal to the great gods. He designates the Igigi as belonging to heaven, the Anunnaki as belonging to the earth. The manner in which he uses the names shows conclusively that, at this early period, the two groups comprehended the entire domain over which spirits, and for that matter also the gods, exercised their power. Indeed, it would appear that at one time the two names were used to include the gods as well as the spirits. At least this appears to be the case in Assyria, and the conclusion may be drawn, from the somewhat vague use of the terms, that the names belong to a very early period of the religion, when the distinction between gods and spirits was not yet clearly marked. However that may be, in Babylonian hymns and incantations the Igigi and Anunnaki play a very prominent part. Anu is represented as the father of both groups. But they are also at the