Page:The Zoologist, 4th series, vol 5 (1901).djvu/289

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Experiments in Hybridity at Pretoria.—I have at present five Zebras (Chapman's), three of which have been interviewed by a Donkey stallion; I am very anxiously awaiting results, which I will not fail to let you know in time. I have been very successful in breeding crosses between Mus chrysophilus and M. decumanus, and have about twenty-four at present. The result of a cross between the ordinary albino Mus musculus with the Striped Mouse (Arvicanthis pumilio) is a peculiarly cream-coloured, not striped specimen, which looks very much like a cream-albino Mouse with black eyes, which stand out very distinct against the cream-coloured fur. I have also bred Galago moholi (Otolicnus galago) and Eliomys nanus with great ease, and am now trying to cross Canis mesomelas with a Collie-Dog, but have not seen any pairing yet, notwithstanding many attempts.— (Director, Zoological Gardens, Pretoria, Transvaal Colony).

[The first experiment detailed above is very opportune, Mr. S.A. Deacon, of Cape Colony, having recently written in the 'Field' that he considers the Quagga to have been originally a cross between Donkey and true or Mountain Zebra.—]

The Winter Singing of the Song-Thrush (Turdus musicus).—I am glad that Mr. Warde Fowler has attacked this subject (ante, p. 212), and I hope that gentleman will work out the question involved to a final conclusion. But I must express surprise at the distinction drawn between the autumn and winter songs of the species. The Thrush is not alone in this matter—the Starling and the Robin are its companions; and I feel convinced, from close daily observation for years at Stroud and Cheltenham in Gloucestershire, and at Eltham in Kent, that in the case of each of the above species there is no definite change of voice from autumn to winter song, but only that gradual progressive development from feeble to strong notes, and from simple to complex strains, which occurs in all song-birds (quickly or slowly) when the season of song approaches. I should be glad if Mr. Warde Fowler would ascertain from several districts whether the Song-Thrush was in voice in October.

What of October singing? Is it autumn or winter song? In September I have heard only an occasional loud note from the Thrush, but