30 EXTERNAL PARTS 



AVheii there are but three toes, the usual arrangement is to 

 have them all three in frmit} This is the same as the arrange- 

 ment in the sparrow, except that the first or hind toe is want- 

 ing, the three toes in front being the second, third, and fourth 

 toes of the usual four-toed birds. Examples of this arrange- 

 ment are found among the plovers. One of our vi^oodpeckers 

 lacks the first toe, and the fourth toe is thrown behind. This 

 gives the last arrangement of three-toed birds ; viz. two in front 

 and one behind.^ 



It will thus be seen that the first toe is in many cases en- 

 tirely wanting. From its absence to its reaching the length 

 and strength of the front toes, there are all possible grades 

 found in the feet of our birds. The kittiwake gull has the 

 hind toe so small and wart-like (often without any claw), 

 that it is readily overlooked by beginners in ornithology. 

 Most of our plovers have just three toes, but the black-bellied 

 plover shows a minute hind one. All of our barnyard fowl have 

 a short hind toe, and in them, as in other birds with the first 

 toe short, it is elevated ' above the level of the front toes. 



Appendages of toes. — Tlie toes of birds have claw-like nails ; 

 these are called claws (or usually nails in this book), and vary 

 much in strength, length, and curvature. They are so strong 

 on birds of prey that they have the special name talons.* The 

 hind claw is very long and almost straight ' in the horned larks. 

 In the grebes, the claws are much flattened* and resemble 

 human nails. The herons and a few other birds have a curi- 

 ous saw-like ridge along the inner side of the middle claw ; in 

 these cases the claw is said to be pectinate.'' 



In many birds, the basal portions of some of the toes are 

 more or less grown together. This growing together reaches 

 the maximum in the kingfisher, where the outer and middle 

 toes are united for half their length.' 



