No. 613] INHERITANCE IN F ANT AIL PIGEON 23 



of this kind is strikingly in favor of a single feather split 

 into right and left parts at the distal end. In all, three 

 cases of this sort were found. 



To the same group are to be referred two cases, one of 

 which is shown in Fig. 14, Xo. 5, Here there is a single 

 feather, but the midrib is split near the end. The vane 



lying between the two midribs is continuous, yet the bend- 

 ing inwards of this part is indicative of its dual nature. 



More extreme are the eight cases of which three are 

 shown in Fig. 16, lowest row. In all such cases there is 

 a large, almost fully formed feather with a smaller, less 

 perfect piece underneath the larger part. The first im- 

 pression is that a piece has been split off the ventral side 

 of the feather by a division in the horizontal plane. A 



