LOPHIIM. XCVI. 173 



Next come the Batrachians, animals bearing close relations to 

 the " central stem " of the fishes, now represented by the Dipnoi. 

 They are decidedly fish-like in their early conditions, but this stage 

 is ultimately outgrown. " The undivided cartilaginous coracoid of 

 Polyterus (a Dipnoan) has a tubercle articulating with diverging 

 rods ; in the one we have the rudiment of the humerus, in the 

 other the representatives of the ulna and radius, while the undif- 

 ferentiated cartilage between the diverging rods is material for the 

 carpal bones, and in bones radiating from that cartilage are the 

 homologues of the metacarpals. The attempts of a primitive ani- 

 mal of such a type to travel on land might develop the fore-limb, 

 and a hind one would follow in sympathy with the other. Then we 

 would have the first of the quadruped vertebrates," the Batrachians. 

 (Gill.} 



