PALEOZOIC ICE-AGES OF SOUTH AFRICA 691 



has been discredited on the failure of a non-essential feature in the 

 original exposition, and the whole question calls for re- examination. 

 And not only the Permian breccias, but conglomerates and breccias 

 of all ages, even in the zone of intense metamorphism, require to be 

 minutely and critically studied; for, as our South African bowlder 

 clays show, the striae and faceting characteristic of ice-action may 

 be preserved in the most unexpected way. 



