84 LABORATORY EXERCISES. 



B. Excretion from insensible perspiration. 



1 . Lay the palm of your hand (when your body 



feels cool) on a cold mirror. What evi- 

 dence do you find of the activity of the 

 skin? 



2. Lay the back of your hand on the mirror. 



a. Do you find any difference between 



the amount of perspiration from 

 the palm and from the back of the 

 hand? 



b. Study your hand on a hot day and an- 



swer the same question. 



44. STUDY OF THE KIDNEY OF THE SHEEP. 



Materials: Fresh kidneys of sheep or pig in capsule, prepared for 

 the pupil as follows : Slit the capsule on convex side enough to allow 

 the kidney to be removed; cut the kidney from the convex border 

 toward the hilum sufficiently to open up the cavity within; replace 

 the kidney within the capsule; probe. 



A. Exterior of the kidney. 



1. Describe the capsule by which the kidney 



is surrounded. 



2. Carefully remove the kidney from the cap- 



sule, taking care not to tear the latter. 

 Where is the capsule attached to the kid- 

 ney? 



3. What is the shape of the kidney? 



4. What is the color of the kidney? Why? 



5. How many tubes can you find connected 



with this organ? Can you suggest the 

 use of any of these tubes? (The depres- 



