It will not be expected that in these brief and desultory remarks I should touch on all, or nearly all, the important points in the discussion respecting the Fixity of Species. Mr. Darwin’s book is in everybody’s hands, and my object has been to facilitate, if possible, the comprehension of his book, and the adoption of a more philosophical hypothesis, by pointing out the weakness of the chief argument on the other side. There is one more argument which may be noticed—the more so as it is constantly adduced with triumph by the one school, and admitted as a difficulty by the other. Its force is so great that it prevents many from accepting the development hypothesis. It is the argument founded on the alleged impossibility of Hybrids continuing the race. More than two or three generations of Hybrids, it is said, can never be maintained; after that, the new form perishes: thus clearly showing how Nature repudiates such amalgamations, and keeps her species jealously distinct and invariable. This argument is held to be the touchstone of the doctrine of species. I wish it were so; because, in that case, the question would no longer be one of hypothesis, since we have now the indubitable proof that some Hybrids _are_ fertile unto the thirteenth generation and onwards. A history of the various attempts which have been made to prove and disprove the fertility of Hybrids, would lead us beyond our limits; the curious reader is referred to the works cited below.[15] One decisive case alone shall be given here, and no one will dispute that it _is_ decisive. The hare (_lepus timidus_) is assuredly of a distinct species from the rabbit (_lepus cuniculus_). So distinct are these species, that any classification which should range them as one, would violate every accepted principle. The hare is solitary, the rabbit gregarious; the hare lives on the surface of the earth, the rabbit burrows under the surface; the hare makes her home among the bushes, the rabbit makes a sort of nest for her young in her burrow—keeping them there till they are weaned; the hare has reddish-brown flesh, the rabbit white flesh; while the odour exhaled by each, and the flavour of each, are unmistakeably different. The hare has many anatomical characters differing from those of the rabbit: such as greater length and strength of the hind legs, larger body, shorter intestine, thicker skin, firmer hair, and different colour. The hare breeds only twice or thrice a year, and at each litter has only two or four; the rabbit will breed eight times a year, and each time has four, six, seven, and even eight young ones. Finally, the two are violent foes: the rabbits always destroy the hares, and all sportsmen are aware that if the rabbits be suffered to multiply on an estate, there will be small chance of hares.