;ii2 



TROPIC AI. WILD l.llK IN IJRITiSII (, LIANA 



FIG. 105. DEVELOPMENT OF THE THIRD DIGIT OF THE ANI 

 a. Partly developed embryo. b. Twenty-four hours before hatching, c. Adult. 



DIGITUS 



The })one structure of the digitus presents several in- 

 teresting features. Two points especially stand out on ac- 

 count of their being peculiar to this bird or its near rela- 

 tives. First is the curious horizontal flattenina: of the third 

 metacarpal. It appears ahnost to be divided into two bones 

 running ])arallel to each otlier and connected by a very 

 thin transparent layer of bone. At tlie proximal end. where 

 it is ankylosed to the second metacarpal, it is broadly flat- 



