AVES. 395 



Head: beak, mouth, nares, eyes (how many lids?), ears. 



Neck : length, natural position, flexibility, etc. 



Wings : arm, forearm, hand. 



Legs : thigh, shank, foot. Where is the heel ? Evi- 

 dences? Note further arrangement and number of 

 digits ; form of the claws ; covering of the tarso-meta- 

 tarsns. 

 Covering of the body. Compare the color of all visible 



parts. 



Select feathers from various parts of the body; study as 

 a type one of the large wing feathers, noting: shaft 

 (quill and rachis), vane (barbs and barbules). 



Compare the other feathers selected with this one. What 

 would you suggest as the prime function of each kind ? 



Arrangement of the feathers. 



On wings: rcmiges (large), primary (on hand) and 



secondary (on forearm) ; coverts. 

 On tail : rectrices, number and arrangement ; coverts. 

 On body (dip in hot water and pluck) : note the pits 

 which have borne the feathers; arrangement of 

 these. Are they uniformly distributed over the en- 

 tire body? 

 Sketch the plucked bird, studying more carefully the regions 



already noted. Locate 



Openings : mouth, nares, ears, cloaca. 

 Queries : 



Is there any connection between the closing of the toes 

 and the flexing of the leg? Has this any use to the 

 animal ? 



Which digits are represented? Are they ecrually devel- 

 oped? 



Which digit is turned backward? How is this deter- 

 mined ? 



Is there a tongue? Are there teeth? Do the nostrils 

 communicate with the mouth? 



What do you consider the function of the nictitating 



