In consequence, there developed two varieties of wedge-writing: the one that may be termed lapidary, used for the stone inscriptions, the official historical records, and such legal documents as were prepared with especial care; the other cursive, occurring only on legal and commercial clay tablets, and becoming more frequent as we approach the latest period of Babylonian writing, which extends to within a few decades of our era.

In Assyria, finally, a special variety of cuneiform developed that is easily distinguished from the Babylonian by its greater neatness and the more vertical position of the wedges.
The origin of all the styles and varieties of cuneiform writing is, therefore, to be sought in Mesopotamia; and within Mesopotamia, in that part of it where culture begins--the extreme south; but beyond saying that the writing is a direct development from picture writing, there is little of any definite character that can be maintained.

We do not know when the writing originated, we only know that in the oldest inscriptions it is already fully developed.
We do not know who originated it; nor can the question be as yet definitely answered, whether those who originated it spoke the Babylonian language, or whether they were Semites at all.

Until about fifteen years ago, it was generally supposed that the cuneiform writing was without doubt the invention of a non-Semitic race inhabiting Babylonia at an early age, from whom the Semitic Babylonians adopted it, together with the culture that this non-Semitic race had produced.

These inventors, called Sumerians by some and Akkadians by others, and Sumero-Akkadians by a third group of scholars, it was supposed, used the "cuneiform" as a picture or 'ideographic' script exclusively; and the language they spoke being agglutinative and largely monosyllabic in character, it was possible for them to stop short at this point of development.