128 KDWAED B. POULTON. 



expressed above concerning the follicular epithelium of Mono- 

 tremes be correct (and of this point I am sure), it will, perhaps, 

 more than any other character, serve to place this order on a 

 totally different level from the other mammalia. It sinks the 

 differences between Marsupialia and Monodelphia in an equal 

 divergence from both. The result is, I think, astonishing; the 

 gap is almost greater than could be expected — not only in the 

 Monotreme^s downward afifinities, but in the upward affinities 

 of the Marsupials. In other points {" The Tongue of Ornitho- 

 rhynchus'^ in this Journal for July, 1883) I have shown 

 indications of transition between the two orders, but there is 

 no such tendency here, where the characters are probably of 

 very deep significance. 



