AVES 399 



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

 Note further arrangement and number of digits ; form of 

 the claws; covering of the tarso-metatarsus. 

 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: remiges (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 entire 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 ani- 

 mal? 



Which digits are represented? Are they equally devel- 

 oped? 



Which digit is turned backward ? How is this determined ? 

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



communicate with the mouth ? 



What do you consider the function of the nictitating mem- 

 brane ? Are the eyes movable ? Do they view the same field ? 

 Do the two together cover the entire field of view ? 

 How much external ear is present ? 

 Are the scales homologous with feathers ? (See reference 



texts.) 

 III. Internal Structures. (The pigeon is a good type for 



anatomical study.) 



The student knows what internal organs and systems of 

 organs to expect in vertebrates, and may well be required 



