Origin of Species Variorum

ornithologists consider our British red grouse as only a strongly-marked race of a Norwegian species, whereas the greater number rank it as an undoubted species peculiar to Great Britain. A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species; but what distance, it has been well asked, will suffice? if that between America and Europe is ample, will that between the Continent and the Azores, or Madeira, or the Canaries, or Ireland, be sufficient? Some few naturalists maintain that animals never present varieties; but then these same naturalists rank the slightest differences as of specific value; and when even the same identical form is met with in two distant countries, or in two quite distinct geological formations, they go so far as to believe that two separate species are hidden under the same dress. Finally, it cannot be disputed that many forms, considered by highly-competent judges as varieties, have so perfectly the character of species that they are ranked by other highly-competent judges as good and true species. But to discuss whether such slightly different forms are rightly called species or varieties, before any definition of these terms has been generally accepted, is vainly to beat the air. ↑

Many of the cases of strongly-marked varieties or doubtful species well deserve consideration; for several interesting lines of argument, from geographical distribution, analogical variation, hybridism, &c., have been brought to bear on the attempt to determine their rank. I will here give only a single instance,— the well-known one of the primrose and cowslip, or Primula vulgaris and veris. These plants differ considerably in appearance; they have a different flavour, and emit a different odour; they flower at slightly different periods; they grow in somewhat different stations; they ascend