62 ELEMENTS OF COMPARATIVE ZOOLOGY. 



in various stages of growth. Can you trace the ducts from 

 either kidney, or reproductive organs ? Where do they end ? 



Open the skull very carefully, beginning at the top and 

 working down on the sides. If the head be cut off and put in 

 alcohol for twenty-four hours or more, the parts of the brain 

 will be better made out. In front are the cerebral hemi- 

 spheres, with the olfactory lobes showing in front and below. 

 Inserted in the angle between the two hemispheres is the 

 cerebellum, and on either side of the latter, and partially 

 covered by the cerebrum, are the optic lobes. What has 

 become of the 'twixt-train ? Do you find the medulla ? 

 Are all the parts of the brain smooth ? Draw the brain 

 from above and from the side. 



The essential features of the skeleton can be made out 

 from the same specimen after boiling. The parts neces- 

 sary are the head, the shoulder-girdle, wing, leg, and a few 

 of the vertebras. What is the shape of the ends of the 

 vertebrae ? In the shoulder-girdle what parts can you 

 recognize ? What name must be given to the wish-bone, or 

 furcula ? (compare the frog.) In the wing humerus, radius, 

 and ulna are readily made out. How many carpal bones 

 do you find? In the "hand" how many fingers can you 

 distinguish? Sketch the carpus and "hand/' with the 

 ends of radius and ulna. In the leg recognize femur 

 tibia, and fibula. W r here is the heel ? What must the 

 bone above the toes be ? 



Are the bones distinct in the skull ? Move the beak 

 upon the skull. Where do the bones slide ? Connecting 

 the angle of the upper jaw with the skull is the quadrate 

 bone. Is it movable ? 



