FERTILITY OF THE HYBRIDS. It is well known that the mule is infertile, and though there are reported to be three eases where a mule has pro duced young, they are doubtful. Evart. in re ferring to the instance of the Paris Jardin de l'Acelimatation mule. doubts whether these ani mals are mules. quoting Avrault's opinion that the Paris mule was an ordinary mare. Darwin states that he knows of no thoroughly well authenticated eases of perfectly fertile hybrid animals. though he adds: "I have reason to be lieve that the hybrids from vaginalis and Reevesii and from Phasianus colchicus with Phasianus are perfectly fertile." The hare and rabbit are supposed to have fertile off spring; the hybrids of the common and Chinese geese (A nscr cygnoides) are fertile, as are hy brids between the common duck and the pintail duck. The crossed offspring from the Indian humped and common cattle interbreed. Caton
has hybridized the Virginia deer with the Ceylon deer and the Acapulco deer, and says that the hybrids seem perfectly healthy and prolific. The Indian (log and coyote are said by Cones to inter breed. ;Ind on the upper Missouri dogs have lawn seen having every appearance of being such hy brids. Hybrids of hares and rabbits have con tinued fruitful for generations; the same is true, says Ilert wig, of hybrids obtained from the wild buck and the domesticated she goat. The Ameri can bison is known to breed with the domestic cattle. and it seems to be a well-established fact that the hybrids are fertile. Ewart states that the Indian buffalo and the American bison pro duce fertile hybrids with the wild ox of Europe. Among fishes, fertile hybrids have been obtained from the carp and goldfish, and from the agar and the brook trout.