118 TELEGONY AND EEVERSION. 



As no mention is made as to the existence of stripes in the 

 immediate ancestors of this striped foal, it may be taken 

 for granted that they were whole-coloured. But one at 

 least of the parents may have been striped at birth. On 

 reading the description of Darwin's colt with the all but 

 invisible sti'ipes it naturally occurs to one that many foals 

 may be striped at birth, but owing to the lines being so 

 subtle they escape the notice of the ordinary observer ; and 

 further, that foals not showing stripes at birth may have 

 passed through a striped stage before birth. 



A year ago Mr. Selous was good enough to tell me of 

 some of his experiences with zebras in South Africa. I 

 was particularly anxious to learn about the coloration of 

 unborn zebras. The origin of stripes has long interested and 

 puzzled natui-alists. It has been suggested that transverse 

 stripes are preceded by longitudinal bands, the longitudinal 

 bands undergoing a kind of segmentation, the segments 

 being afterwards joined together to form transverse stripes. 

 Fortunately Mr. Selous had seen an unborn zebra, which 

 though distinctly striped looked as if it was quite destitute 

 of hair. But as the zebra's skin is of a nearly uniform 

 dark colour throughout, there can be no doubt that with the 

 help of a lens hair rudiments at least would have been 

 detected in this fcstus. From the information Mr. Selous 

 was able to give, and from an account of a foetal zebra 

 given by Sparniau, I am satisfied that the transverse 

 stripes of zebras are not preceded by longitudinal bands. 

 In young zebras the stripes have often a wavy, almost a 

 zigzag appearance. Hence the transverse stripes, though 

 not derived from longitudinal bands, may in some cases be 

 represented for a time by spots, which by being somewhat 

 out of line give rise when welded together to more or less 

 wavy stripes. Are the horse foals, which are whole- 

 coloured at birth, marked like a zebra before birth ? or, Is 

 the striped phase in the ancestral history frequently entirely 

 skipped by an abbreviation in the development process? 

 As I have in my possession a series of foetal horses ranging 

 from three weeks to over ten months, I am able to state 



