QUESTIONS 
495 
The worms that cause trichinosis are closely related to hook¬ 
worms. This disease is due to the round-worm, trichinella, 
and comes from eating partly cooked pork that has these 
worms in the flesh. This is becoming a rare disease, due to 
the painstaking inspection of slaughter-houses by the gov¬ 
ernment. Flat tapeworms are often found in dogs, cats, 
and fish. Occasionally one gains access to the intestinal 
tract of man. Here it rapidly grows into the adult stage, 
living upon the food that should go to nourish man. 
SUMMARY 
Disease prevents us from working as we do when we are 
well. Most diseases are unnecessary and preventable, es¬ 
pecially those which are caused by plants or animals living 
as parasites in our bodies. In most of the biological diseases 
some definite poison produced by the parasite is taken into 
the body, and this is the chief cause of disease. Tuber¬ 
culosis, the “ great white plague,” is caused by a plant 
named bacillus tuberculosis and often referred to by phy¬ 
sicians as “ Tb.” One can get well if the body is able to 
overcome the poisons secreted by these minute plants. 
Each disease caused by bacteria has its own special history 
and the symptoms of the disease are definite and distinct. 
Influenza is probably a germ disease, but the exact kind of 
bacteria is still unknown. It was epidemic over nearly the 
whole world in 1918 and 1919. Malaria is a disease due to 
a protozoan parasite living in the blood corpuscles of man. 
These parasites are introduced into the blood through the 
bite of Anopheles mosquitoes. 
QUESTIONS 
What are the biological diseases ? How are these diseases caused ? 
How many kinds of tuberculosis are there? Is diphtheria a germ 
disease? Are colds germ diseases? Describe malaria. What effect 
has malaria had upon the settlement of our country? This is a home 
study question. 
