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



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



FlG. 7. Persis- 

 tent Coccyx in 

 Man. 





Fir,. 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 



