We must, of course, add to human malformations the many abnormal phenomena occurring in the young of animals in which the determining factor is again the =significance= attached to all kinds of malformation among human beings and animals as birth-omens. This factor must be taken as our point of departure; it furnishes a reason not merely for the rise of the belief in all kinds of fabulous creatures but also for the elaboration and the persistency of the belief and for its embodiment in the religious thought of peoples. It is because the malformation is an omen that it leads to further beliefs and fancies. The direct association of the belief in fabulous creatures with birth-omens in Babylonia and Assyria lends a presumption in favor of the same association among the Greeks. If, therefore, we can trace the attachment to birth-omens among Greeks and Romans to the Euphrates Valley, we will have found a reasonable explanation for the part played by monsters and fabulous beings in the mythology and the religion of the Greeks and Romans. Further than this, it is not necessary to go. It is not essential to the establishment of the thesis to trace =all= the fabulous beings of classical mythology to actual malformations. The factor of fancy would lead to the extension of the sphere far beyond the original boundaries; nor is it necessary to find parallels to all the creatures of Greek and Roman mythology in Babylonian and Assyrian literature or art in order to justify the dependence of the former upon Babylonian-Assyrian birth-omens. No doubt the Greeks, more particularly, developed the conception in their own way, adding other features to it, just as they modified Babylonian-Assyrian astrology in adapting it to their environment and their way of thinking, and just as the Etruscans and Romans modified the Babylonian-Assyrian hepatoscopy[223]. All that is claimed here is that the =conception= of monstrous and fabulous beings is a direct outcome of the importance attached to Birth-omens; and since the Babylonians and Assyrians are the only people who developed an elaborate system of divination in which the interpretation of birth-omens constituted an important division, and which spread with the extension of Euphratean culture to Asia Minor and thence to Greece and Rome, I claim that the ultimate source of the belief itself is to be sought in the Euphrates Valley.