Bibliographical Notice. 77 



The above views strongly support those held by Settegast *, 

 Weisniann f, Kuhn J, Nathusius §, as well as some authorities in 

 this country ||, though it is opposed to Herbert Spencer *f[, Dr. Harvey 

 of Aberdeen **, and others' explanation of the phenomenon. 



Nor docs the " Saturation " hypothesis find any more favour with 

 Prof. Ewart. He quotes Bruce Lowe's definition tt of it, that at 

 " each mating and bearing the dam absorbs some of the nature or 

 actual circulation of the yet unborn foal, uutil she eventually 

 becomes saturated with the sire's nature or blood, as the case may 

 be." Prof. Ewart proceeds to show from others' and his own 

 experiments that supposititious cases of saturation are but more 

 pronounced ones of reversion, due to better nutrition of the germ- 

 cells &c. . 



Concerning sterility in equine hjbrids, he thinks it is not in 

 obedience to any natural law they are so. His experiments lead 

 him to believe that preferential mating accounts for much, especially 

 in the horse tribe ; while it is noteworthy that a number of species 

 of other animals and plants yield when crossed fertile off'spring. 



Prof. Ewart enters into detail, and nicely figures the peculiarities 

 and ditferences of the so-called species of zebras and hybrids. 

 He considers the Somali zebra {E. Greviji) the most primitive 

 form. This with the mountain zebra {E. zehra) and the group of 

 Eurchell's zebras are to him distinct types, but they cannot be 

 readily distinguished from each other by their markings. There- 

 fore we may add that Mr. E. I. Pocock's excellent paper on " The 

 Species and Subspecies of Zebras " (Ann. & Mag. Nat. Hist. xx. 

 1897) may well be studied for comparison, this author's presumed 

 subspecies being well defined. He notes the gradual lessening of 

 the stripes from north to south, being absent in the hindqaarterq of 

 the quagga south of the Orange Eiver. See also Sir W. Flower's 

 remarks ('The Horse,' 1891) and P. L. Sclater's various memo- 

 randa on zebra species (P. Z. S.). 



The question is started by Prof. Ewart, "Were the ancestors of 

 the horse striped ? And as side-issues thereon he discusses the 

 points as to face and head, neck, body, and leg-stripes. He con- 

 cludes that the ancestral horse was striped in a manner intermediate 

 between the common and Somali zebras. The croup- and rump- 

 stripes he regards as comparatively a recent acquisition in the zebras. 

 He suggests though that in pigs spots, and not dark bands, were 

 the original coloration, these afterwards merging into stripes &c. 



* ' Die Thierziecht,' Band i. 



t ' The Germ-Plasm : a Theory of Heredity.' English translation bv 

 Prof. W. N. Parker, ^ 



\ An experienced veterinarian of Halle, quoted by Weismann and 

 Ewart. 



§ * Ueber Shorthorn Pindvich,' &c. 



II See works of Darwin, Romanes, Galton, &c. 



^ 'Contemporary Review,' 189^3, (fee. 

 ** A remarkable effect of cri ss-breeding quoted by Ewart. 

 ft ' Breeding on the Figure System,' quoted by Ewart. 



