GLANDS AND THE WORK OF EXCRETION 213 



2. What are the parts common to all glands ? What purpose is 

 served by each of these parts ? 



3. How do tubular glands differ in structure from saccular glands ? 

 What is a racemose gland ? Why so called ? 



4. Describe the nature of the secretory process. 



5. What conditions render necessary the formation of waste mate- 

 rials in the body ? Why must these be removed ? 



6. How do the waste materials get from the cells to the organs of 

 excretion ? 



7. Show by a drawing the connections of the kidneys with the 

 large blood vessels and the bladder. Name parts of drawing. 



8. In what do the uriniferous tubes have their beginning ? In 

 what do they terminate ? With what are they lined ? 



9. Why should the blood pass through two sets of capillaries in 

 the kidneys ? 



10. Bright's disease of the kidneys affects the uriniferous tubes and 

 interferes with their work. What impurity is then left in the blood ? 



11. Trace water and salts from the Malpighian capsules to the 

 bladder, naming parts through which they pass. 



12. Trace carbon dioxide from the cells to the outside atmosphere. 



13. How does the quantity of material introduced into the body 

 compare with that which is removed by the organs of excretion? 



14. Name two ways of lessening the work of the kidneys. 



15. Why is the drinking of plenty of pure water a healthful prac- 

 tice? 



PRACTICAL WORK 



To suggest the Double Work of Glands. Prepare a simple filter by 

 fitting a piece of porous paper into a glass funnel. Through this pass 

 pure water and also water having salt dissolved in it and containing 

 some sediment, as sand. The water and the dissolved salt pass through, 

 while the sediment remains on the filter. Now substitute a fresh piece 

 of paper in the funnel and drop on its surface a little solid coloring 

 matter, such as cochineal. Again pass the liquid through the funnel. 

 This time it comes through colored, the color being added by the 

 filter. Compare the filter and materials filtered to the gland and the 

 materials concerned in secretion (blood, the liquid secreted, substances 

 added by the gland, etc.). 



