PERSONAL AND CIVIC HYGIENE 341 



/. Disinfecting rooms with 1 % carbolic acid, sunlight, and formalin. 

 g. Disinfecting persons and their clothing. 



2. Stop germs from entering the body by : 



a. Keeping flies away from food. 



b. Drinking from clean vessels, pasteurize them as well as the 



milk and water. 



c. Keeping off mosquitoes, fleas, and bedbugs. 



d. Burning the sputum from patients. 



e. Filtering the water 

 /. Disposing of sewage. 

 g. Avoiding alcohol. 



h. Using individual drinking cups at public drinking places. 



3. Develop in the body a substance which kills harmful germs by : 



a. Good food, rest, air, exercise, and sunlight. 



b. Antitoxins, as against diphtheria, etc. 



c. Vaccines, for smallpox, hydrophobia, etc. 



SUMMARY VIII 



A summary of some biological processes in organisms, 

 with special reference to reproduction, heredity, and hy- 

 giene. 



a. The Flower 



Considerations. 1 . What is the principal reason for the existence of 

 any flower ? 



2. What is produced by a complete flower? 



3. What is the function of pollen ? Of ovules ? Of stamens ? Of pistils ? 



4. Explain Figure 85. What does it show ? 



Note. The cell in the pollen grain which grows into the pollen tube 

 is known as the sperm cell. The cell in the ovule which fuses with the 

 sperm cell is called the egg. When these fuse they form a single cell, 

 the fertilized egg. The egg immediately begins to develop (see Prob. 

 XXVI, a), to form a minute prophecy of the future plant, which is called 

 the embryo. This stops growing when the seed is ripe, in zones with a 

 winter climate or a dry season, to again grow and develop when proper 

 conditions of temperature and moisture are present. 



Conclusions. 1 . Does there seem to be any reason for the fusion of 

 the sperm cell with the egg? Note. The two cells being different, 

 may it be the case that each cell supplies the other with something that 

 it lacks ? 



