TEST QUESTIONS FOR STUDENTS 921 



or epiblastic ? vVhat are (6) wholly endodermic or hypoblastic ? 

 What are (c) wholly mesodenuic ? Give an example of a structure 

 (d) partly ectodermic and partly mesodennic in origin. Give an 

 example of a structure', e) paitly endodermic and partly mesodennic. 



75. Give a short account of the skeletal peculiarities in the hind- 

 leg of one of the following : Frog, marine turtle, bird, horse, cow, bat. 

 Contrast the skeleton of the leg chosen with that of man's leg. 



76. State in a couple of hues what is remarkable in the following 

 pieces of skeleton — the coracoid in typical mammals, a bird's rib, 

 a bird's quadrate, a frog's proximal tarsals, the vertebra? of the 

 Bony Pike. 



yy. What is a notochord ? Describe its condition in the adult 

 Amphioxiis, lamprey, dogfish or skate, and mammal. 



78. What is the difference between a " membrane boue " and a 

 ■■ cartilage bone " ? 



79. Submit a classification of the Chordate phylum, and indicate 

 the levels at which the following structures began — skull, jaws, paired 

 limbs, digits, lungs, foetal membranes. 



80. Make short notes on the following structures : — a snake's vertebra, 

 a bird's columella, a tortoise's plastron, a placoid scale, a frog's 

 sternum* 



81. Make a short note explaining what is peculiar about each of 

 tae following : — A skate's large intestine, a frog's tympanum, a snake's 

 slough, a bird's syrinx, a mammal's diaphragm. 



82. Make a drawing of the brain of a fish, and explain how it differs 

 Irom that of a crayfish and from that of a rabbit. 



83. Give a general account of the development of the skull in a 

 aogfish or skate, and explain what complications have occurred in 

 the case of a frog. 



84. In what respects does the circulation in Fishes differ from that 

 in higher Vertebrates ? 



85. Explain the general nature of typical gills in fishes. In what 

 respects do they differ from the gills of a crayfish ? What is pecuHar 

 about the gills of a young Elasmobranch, a young Lepidostren, and 

 a tadpole ? 



86. Classify the different kinds of scales on fishes. How do they 

 ail differ from the scales of reptiles ? 



87. Contrast the important characters of the Dipnoi with the 

 animals immediately above them and immediately below them in the 

 Vertebrate scale. 



88. Give an illustrated account of several different shapes among 

 hishes. [(i) The typical torpedo-shape, oval in section, becoming 

 cylindrical in section in eels, becoming globular in globe-fish. 

 (2) Flattened from above downwards, as in skate. (3) Flattened 

 from side to side, and swimming on one side, e.g. bony flat-fishes 

 of plaice type. Flattened from side to side and swimming vertically, 

 as in John Dory. (4) Laterally compressed and much elongated, as 

 in oar-fish, gunnel. (5) Peculiar shapes, as in sea-horse.] 



89. Mention several deep differences between a skate and a flounder. 

 [The skate is a gristly fish, the flounder bony, Elasmobranch and 

 Teleostean respectively. The skate is flattened dorso-ventrally, and 



