Living specimens in cages, mounted specimens, pictures, charts, lantern slides, etc. _Directions._ Before taking up the study of the squirrel in the laboratory a trip should be made to some park or wooded region and the habits of squirrels noted. Take your camera and try to take some snapshots. After the laboratory exercise visit some museum or zoölogical garden and study the relatives of the squirrel. _Observations based upon field work._ 1. What different postures does the squirrel assume? 2. What does it do when frightened? 3. What use have the forelegs other than locomotion? 4. How does a squirrel go up a tree? down? from branch to branch? State all the forms of locomotion you have noticed. 5. What is the appearance of the tail? What is the position of the tail when the squirrel is sitting? running? on a branch? Describe any motions of the tail you noticed. Is there anything expressed by these motions or are they without meaning? 6. Tempt the squirrel with some nuts. State the evidence that leads you to think that the squirrel is alert, timid, curious. Do you think the squirrel acts most from instinct or as the result of intelligence? 7. In what various ways does a squirrel attempt to escape notice? What does it do when you chase it? _Observations in the laboratory._ 1. What divisions are there to the body? What is the length of the neck? the length and appearance of the tail? 2. What is the relative length of the legs as compared with the body? How does the length of the front and hind legs compare? 3. Does the animal walk on its toes or on the sole of its foot? How many toes on each foot? What is the length of the claws? For what could they be used? 4. Offer the squirrel various kinds of food and see if it has a choice. Describe its methods of eating. 5. Note the position of the eyes, the shape of their surface, and the shape and size of the pupil. How many eyelids do you notice? Why do the squirrel's eyes appear so "bright"? Are eyebrows, eyelashes, or tear glands present? 6. Note the size, shape, and appearance of the squirrel's external ears. 7. What movements of the nostrils do you notice? For what does a squirrel chiefly use his nostrils? What explanation can you suggest for the nostrils, eyes, and ears having the same relative position in all vertebrates? 8. How does a squirrel protect itself? 9. Smear the feet of a squirrel with ink and allow it to run over a roll of clean paper as in the case of the rabbit. How do its tracks differ from those of the rabbit? _Summary._ 1. What are the general characteristics of the squirrel? 2. To what kind of life is it adapted? 3. What adaptations has the squirrel to protect it from its enemies? 4. What characteristics make the squirrel a good pet? What objections to it? Library Exercise on Rodents 1. General characteristics and examples of rodents. The teeth of rodents.