Origin of Species Variorum

rose or oak-tree. In all organic beings the union of a male and female elemental cell seems occasionally to be necessary for the production of a new being. ↑ In all, as far as is at present known, the germinal vesicle is the same. So that every individual organic being starts from a common origin. If we look even to the two main divisions— namely, to the animal and vegetable kingdoms— certain low forms are so far intermediate in character that naturalists have disputed to which kingdom they should be referred, and, as Professor Asa Gray has remarked, "the spores and other reproductive bodies of many of the lower algæ may claim to have first a characteristically animal, and then an unequivocally vegetable existence." Therefore, on the principle of natural selection with divergence of character, it does not seem incredible that, from some such low and intermediate form, both animals and plants may have been developed; and, if we admit this, we must admit that all the organic beings which have ever lived on this earth may have descended from some one primordial form. .. .. .. .. .. ... The case is different with the members of each great class, as the Vertebrata, the Articulata, &c.; for here, as has just been remarked, we have in the laws of homology and embryology, &c., distinct evidence that all have descended from a single parent.

When the views advanced by me in this volume, and by Mr. Wallace in the Linnean Journal, or when analogous views on the origin of species are generally admitted, we can dimly foresee that there will be a considerable revolution in natural history. Systematists will be able to pursue their labours as at present; but they will not be incessantly haunted by the shadowy doubt whether this or that form be in essence a species.