TEST QUESTIONS FOR STUDENTS 923 



102. Make a drawing of the bones of a bird's wing and mention five 

 important differences between them and the bones of your arm. 



103. Give an iUustrated account of the development of the central 

 nervous system in a backboned animal, such as the chick. 



104. Contrast a running (Ratite) bird with a flying (Carinate) bird in 

 order to bring out the differences associated with their different habits. 



105. Describe the whole vertebral column of a Carinate bird, and 

 explain how each region is adapted to particular active or passive 

 functions. 



106. What are the various uses of feathers ? 



107. Describe the structure of a typical feather and give a general 

 account of its development. What are the other kinds of feathers ? 

 How do the pennae of running-birds differ from those of flying-birds ? 



108. Explain briefly and simply what is meant by the following 

 terms applied to parts of the bird's skeleton : — (i) A carpo-metacarpus. 

 (2) A tibio-tarsus. (3) A tarso-metatarsus. (4) A syn-sacrum. (5) A 

 pygostyle. [(i) A fusion of half of the wrist bones with the whole of 

 the palm bones. (2) A tibia, to the lower end of which the upper row 

 of ankle bones has been fused. (3) A fusion of the lower row of ankle 

 bones to three fused metatarsals. (4) A fusion of one or two thoracic 

 vertebras, all the lumbars, all the true sacrals, and half of the caudals, 

 to form a long support to which the ilia are fused. (5) A terminal • 

 fusion of caudal vertebrae, like the urostyle in the frog, the coccyx in 

 man.] 



109. Name in order the various regions of the food-canal in a pigeon, 

 and explain what happens in each region. 



no. How is a bird adapted to bipedal progression ? [If a perpen- 

 dicular be dropped from the acetabulum, much of the bird's body and 

 weight is in front of this. Hence the adaptiveness of a long, strong 

 grip of the backbone — the ilia fused to the syn-sacrum. Also adaptive 

 in connection with lighting on the ground from flight is the suppression 

 of free ankle bones. Also adaptive is the leverage of the relatively long 

 and expanded toes.] 



111. What are the salient features of a bird's skull. [Enlarged tri- 

 angular premaxillae, forming a beak ; a complex lower jaw, articulating 

 with the quadrate which is movable ; one occipital condyle ; a delicate 

 infra-temporal bar, composed of jugal and quadrato-jugal ; relatively 

 large orbits ; no teeth in modern birds ; and so on.] 



112. What reasons have we for believing that birds evolved from 

 a Reptilian stock ? [(a) Historical, e.g. reptilian characters of 

 ArchcBopteryx, avian characters of some Dinosaurs : (&) Anatomical, 

 e.g. complex lower jaw articulating with the quadrate, inter-tarsal 

 ankle-joint, scales ; (c) Embryological, the close resemblance of the 

 very young bird embryo to the very young reptile embryo.] 



113. How does an embryo bird breathe before it is hatched ? 



114. Mention two reptilian features in a bird's hind-leg. 



115. The quadrate is a very important bone in a bird's skull. What 

 has become of it in mammals ? 



116. Make a detailed comparison between a bird's respiratory 

 system and a mammal's. 



117. How does a young bird get out of the egg-shell ? 



