Evolution 



present. Horses with this peculiarity have occurred with some 

 frequency, probably before, and certainly since, the most famous 

 of their kind, which Julius Caesar rode. It seems reasonable 



FiG. 7.- -Persis- 

 tent Coccyx in 



Man. 



FIG. 6. Horse's Foot, with well-developed Side Digit. 



From Bateson's Materials for the Study of Variation (Macmillan). 



FIG. 8. Persistent 

 Gill Slits in Man. 



to regard this peculiarity as a return to the old ancestral 

 condition illustrated before, in which the side toes were well 

 developed. The same applies to the instance of a persistent tail 

 and persistent gill slits in man (Figs. 7 and 8), and to many 



12 



