Altogether beyond such a general admission as this, however, it must be obvious that in the mass of deeply interesting material now before us, there lies a considerable number of truths needing to be gathered into generalized form, bearing upon the laws of nature applying to living organism. As records of details are extended before us, the marvels of structure are obvious. The multifarious contrivances become quite startling, until we are ready to lose our reckoning in the very multiplicity of facts narrated. In order to make sure of general result, we need to draw off somewhat from details,--to be content even to lose sight of many of them,--in order to gain a position, sufficiently removed for a sight of general relations. In attempting this it is clear that there are certain truths bearing on the preservation and development of species in the vegetable kingdom, and an analogous set of truths as to the animal kingdom, and above these, possibly still more important for general appreciation of the universe as a whole, a body of truth as to the relations of plants and animals. As to the first of these, it seems obvious that within the single field of observation presented by orchids,--comparatively narrow, in view of the wide domain of the vegetable kingdom, and yet astonishingly extensive, on account of the richness of detail,--there is a large body of evidence to support the theory of origin of species by selection and adaptation. Whether all the orchideæ now found in existence have sprung from one order of plant, or from several, the testimony appears ample to support at least the following conclusion as presented in the words of Mr. Darwin, "that the now wonderfully changed structure of the flower is due to a long course of slow modification,--each modification having been preserved which was useful to the plant, during the incessant changes to which the organic and inorganic world has been exposed."[CE]