Such delineations of the cross as we find embodied in ancient aboriginal art represent only the final stages of its evolution, and it is not to be expected that its origin can be traced through them. In one instance, however, a direct derivation from nature is suggested. The ancient Mexican pictographic manuscripts abound in representations of trees, conventionalized in such a manner as to resemble crosses; these apparently take an important part in the scenes depicted. By a comparison of these curious trees with the remarkable cross in the Palenque tablet, I have been led to the belief that they must have a common significance and origin. The analogies are indeed remarkable. The tree-cross in the paintings is often the central figure of a group in which priests offer sacrifice, or engage in some similar religious rite. The cross holds the same relation in the Palenque group. The branches of these cross-shaped trees terminate in clusters of symbolic fruit, and the arms of the cross are loaded down with symbols which, although highly conventionalized, have not yet entirely lost their vegetable character. The most remarkable feature, however, is not that the crosses resemble each other in these respects, but that they perform like functions in giving support to a symbolic bird which is perched upon the summit. This bird appears to be the important feature of the group, and to it, or the deity which it represents, the homage or sacrifice is offered. These analogies go still farther; the bases of the cross in the tablet and of the crosses in the paintings are made to rest upon a highly conventionalized figure of some mythical creature. A consideration of these facts seems to me to lead to the conclusion that the myths represented in all of these groups are identical, and that the cross and cross-like trees have a common origin. Whether that origin is in the tree on the one hand or in a cross otherwise evolved on the other I shall not attempt to say.