412 Mr. R, 1. Pocock on the Colours of 



In tapirs the only wliite spots which persist to maturity* 

 are those on the rim of the ears, and on the fetlocks in 

 some specimens. In all zebras the tips of the ears are 

 also -Nyhite ; but some young tapirs, at all events, also show 

 white spots on the back of the ear behind, and the back 

 of the ears in all zebi-as has a varying amount of white. 

 All zebra?, too, have a varying amount of wliite on the fetlocks. 

 In four young tapirs mounted in the Natural History 

 Museum, and referred to the four species T. terrestrisy 

 T. roiilini, T. bairdi, and T. tndi'cus, there is a broad dark 

 brown spinal area, defined on each side by a white stripe, 

 sometimes more or less broken up into spots, and extending 

 from the base of the neck on to the hind-quarters. In one 

 of them, T. terrestns, this area is itself spotted witb white in 

 the middle line. In the young of T. bmrdi, which apparently 

 shows the white pattern in an evanescent stage, the dorsal 

 white stripes are only just visible; but they are there never- 

 theless. Gray also noticed these dorsal white stripes in the 

 young specimens he described f. In all zebras, all Asiatic 

 asses, the typical African ass, Prjevalsky's horse, and many 

 domestic horses there is a dark spinal line, narrower or 

 broader according to the species. This dark spinal line is 

 defined by a pale line as far forwards as the withers in some 

 races of Asiatic asses, and at least as far as the middle of the 

 back in some zebras, e. g. JE". grevyi; and the pale line is 

 represented on the neck of many horses and asses, both 

 African and Asiatic, by the outer pale portion of the mane, 

 the middle of which is always black like the spinal line J. 

 If it be just to regard as geneticallj^ related the dark spinal 

 area set off by a pair of white stripes in young tapirs and in 

 existing Equidse, it follows that the pale dorsal longitudinal 

 lines in the horses are the stripes and the dark spinal area 

 part of the ground-colour. The mane of zebras fully bears 

 this out, for it is perfectly evident that the white marks, 

 which, be it noted, are continuous with those of the neck, are 

 the stripes. They merely form superficial tufts on the black 

 mane. 



Now and again the white marks on young tapirs, especially 

 across the sacral region, form short transversely set stripes, 



* In tbe adult Malayan tapir the whole of the posterior half of the 

 body is white. Presuiuablj^ this white area results from the extension 

 and fusion of the white pattern on this area in the young. 



t P. Z. S. 1872, pp. 483-492. 



i Unless my memory is at fault, Prof. Cossar Ewart told me some 

 time ago in conversation that he considered the definition of the dark 

 spinal line by two light lines to be a primitive feature in the Equidse. 



