2l8 BACTERIA, YEASTS, AND MOLDS 



feelers on the head of the dangerous species, rather than 

 three, as in the harmless form (Fig. 70, a and b), and the 

 method of lighting with the body held in a straight line 

 (Fig. 70, b', b", b'"), rather than bent, as in the harmless spe- 

 cies (Fig. 70, a' and a"). It must also be remembered that 

 not all mosquitoes, even of the harmful species, will be dan- 

 gerous. Only those that have sucked the blood from mala- 

 rial patients will contain the parasites and be able to transmit 

 the disease. In other words, of all the mosquitoes that may 

 bite us in summer only a few are likely to be infected and 

 produce any trouble. We may be bitten thousands of times 

 and still be free from malaria, while the next mosquito that 

 bites us may inoculate us with these parasites. 



That family is the best protected against malaria that is 

 the best protected against mosquitoes. If we live in a region 

 where malaria abounds, it is somewhat dangerous to remain 

 out of doors during the night, or even in the early part of the 

 evening, unless properly protected. At this time mosquitoes 

 are most likely to be flying about. From this fact arises the 

 belief that night air is dangerous. It is not the night air that 

 produces the trouble, but the mosquitoes in the air. It is also 

 evident that the best method of protecting a household from 

 malaria is by the use of mosquito netting. It is a curious fact 

 that its use at our windows and doors is the best protection 

 from these microscopic parasites, inasmuch as mosquito net- 

 tings will keep mosquitoes from the houses and will reduce 

 the chances of contagion. This is not a matter of theory 

 only, for it has been found by careful observation and experi- 

 ment that the simple procedure of covering doors and win- 

 dows of houses with mosquito netting has produced a marked 

 decrease in the amount of malaria in these dwellings. 



