They were called Rabboth (great Midrashim) to distinguish them from preceding smaller collections.
There are also Midrashim on the Canticle, Ruth, Ecclesiastes, Esther and the Psalms, belonging to this later period, the Pirge R.
Even in the time of the later Amoraim there is no mention of a written Palestinian Targum, though the official Babylonian Targum is repeatedly referred to in the Babylonian Talmud, in the Midrashim, and at times also by Palestinian Amoraim.
Later Jewish and Christian speculation followed on the lines of the angelology of the earlier apocalypses; and angels play an important part in Gnostic systems and in the Jewish Midrashim and the Kabbala.
Both contain Halaka and Haggada, although the Mishna itself is essentially Halaka, and the Midrashim are more especially Haggadic; and consequently further information bearing upon Midrash must be sought in the art.