QENERAL INTRODUCTION. XClll 



devoid of flagella or tails are not likely to be of any use, 

 it is practically impossible to say whether any given 

 feraa.le germ-cell would, if fertilised, develop into a new 

 individual. The fact, however, that in the oldest of the 

 two zebra hybrids examined there was a follicle enclosing 

 presumably a nearly ripe germ-cell favours the view often 

 advocated, that female mules are at least occasionally 

 fertile, and at the same time encourages us to believe 

 that the Kapurthala potter's mule is the actual mother of 

 the foal found in her possession last August. I ought, 

 however, to say that a three-year-old mule (ass c? -horse ? 

 hybrid) from the New Forest has so far proved sterile 

 alike with Shetland and Welsh ponies, and with the 

 zebra 2 -ass (^ hybrid already mentioned, and that a 

 nine-year-old zebrinny (horse-zebra hybrid) seems also to 

 be sterile with both Arab and Clydesdale horses. 



I intended discussing in this introductory chapter the 

 habits and instincts of young foals, the rate of growth of 

 foals and hybrids, and tjie use of stripes in the Equidte ; 

 but a consideration of these and other questions may very 

 well be deferred until I have completed the first part of 

 a memoir ' On the Development of the Horse,' and a 

 small work ' On Zebras and Zebra Hybrids.' 



I have, in conclusion, much pleasure in expressing my 

 great indebtedness to Lord Arthur Cecil, Mr. Wilfrid 

 Scawen Blunt, the Hon. Walter Rothschild, and Lady 

 Meux. I am also not a little indebted to Sir William 

 Flower, K.C.B., F.R.S., Mr. Oldfield Thomas and Mr. 

 Pocock of the Natural History Museum, London, Professor 

 Mettam, B.Sc, of the Royal (Dick) Veterinary College, 

 Edinburgh, Mr. Dixey, M.A., of Wadham College, Ox- 

 ford, and Professor Stewart, F.R.S., of the Royal College 

 of Surgeons' Museum, London. To Mr. Alfred E. Pease, 

 M.P., Mr. Rowland Ward, Mr. Arthur H. Neumann, and 

 Mr. C. V. A, Peel I owe my best thanks for the loan of 

 valuable skins ; and I must add that I owe much to the 

 writings of Mr. Darwin, Mr. Tegetmeier, Sir Walter 

 Grilbey, Bnrt., and Herr von Natliusius. 



