N. GYLDENSTOLPE, HEEL-PADS IN CERTAIN BIRDS. 



9 



'■'%>)^^ 



are placed along the sides of the pad. On the posterior half 

 of the pad the cusps of the papillae are directed upwards 

 and on the anterior part downwards, thus exactly as in the 

 Capitonidce. The older the bird grows, the more the pointed 

 cusps are worn off, as may be seen from fig. 13 which is 

 drawn from a specimen, in which they are almost worn off. 

 The remains of the tubercles are, however, 

 always visible until the bird has assumed 

 the fully adult plumage. 



In other species of Woodpeckers, 

 which I ha ve been able to examine, viz. 

 Dryobates major major Linn., Dry olates 

 minor minor Linn., Hemicercus canente 

 Blyth and Chrysocolaptes guttacristatus 

 TiCK. a similar structure and arrangement 

 also occurs. In the subfamily lyngince 

 these same pads have been observed by 

 GuNTHER as mentioned above (Ibis 1890, 

 p. 411 — 412) a case which however, I have been unable to 

 confirm by the lack of material at present. 



Fig. 13. 

 Picus viridis viridis 

 Linn. Left tarsas. 



Vi. 



-^\ 



y mr\ 



\ 11' 



Fig. 14. 



Dryohates minor 



minor Linn. Lateral view 



of right tarsus. "A- 



Fig. 15. 



Dryohates minor 



minor Linn. 



Right tarsus. */i- 



Fig. 16. 

 Dryobates minor 



tninor Linn. 

 Risrht tarsus. ^/i. 



In the families dealt with above, these pads are most 

 highly developed, though they also occur in birds belonging 



