EXPLORATIONS AND PROJECTS 



1 To find the location of the various endocrine glands, dissect a thoroughly 

 anesthetized laboratory animal, identify from charts and examine the form, struc- 

 ture and texture of as many of the glands as possible. 



2 To demonstrate the effect of thyroid extract, feed animals on diets that 

 differ only in its presence. Place a male and a female rat, from three to four weeks 

 old, in each of two cages; feed both pairs the same diet.^ To the rats in one cage 

 feed, in addition, half of a one-tenth-grain tablet of thyroid extract each day. The 

 half tablet must be olaced in the mouth of each rat to make sure that it is taken in. 

 Keep record of weight; make a graph of daily growth. Compare the behavior, as 

 well as the growth, of the rats in the two cages. In what ways does the thyroxin 

 seem to afl^ect the personality.'^ Compare results of this experiment with known 

 cases of hyperthyroid persons. 



3 To find the effect of thyroid extract on the development of tadpoles, feed 

 two sets the same diet, but supply one set with thyroid extract. Place the tadpoles 

 from the same batch in two aquariums. Feed both sets on flour, but add to the 

 flour for one set a crushed tablet of thyroid extract. Continue watching for several 

 weeks. Describe the differences observed between the two sets of tadpoles. 



4 To demonstrate the relation of emotions to muscular activity, to facial ex- 

 pression, and to posture, observe your classmates under various situations that 

 involve distinct emotions or attitudes. What facial movements are involved in 

 "registering" anger, anxiety, fear, affection, cruelty, or eagerness? 



Have an individual with his back to the class assume postures intended to 

 express distinct emotions, and see how generally the intent can be recognized. 



Attempt to combine posture and gestures of one mood with an imaginary 

 situation that would put one in a contrasting mood. For example, try to loo}{ 

 friendly and helpful while imagining yourself in a situation that would make you 

 feel resentful or full of hate — or vice versa. Or try to look as if you were having 

 a hilarious time while imagining yourself at the funeral of a person you love and 

 respect — or the reverse. In each case, note the movements or combination of 

 movements that appear especially appropriate, or especially inappropriate, for the 

 mood or emotion under consideration. 



QUESTIONS 



1 What factors influence the rates at which the various chemical processes 

 take place in higher animals? 



2 In what respects are the hormones Hke vitamins? like enzymes? unhke 

 either vitamins or enzymes? 



3 How are the internal secretions distributed throughout the body ? 



4 Which of the specific hormones affect growth? Which affect energy 

 liberation? Which affect the rate of metabolism? 



^The complete diets suggested on page 112 are suitable. A half-and-half mixture of rolled 

 oats and whole-wheat flour, with milk to drink, is very satisfactory. Certain prepared dog 

 biscuits are good. 



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