268 



CIVIC BIOLOGY 



The first school able to report complete freedom from this parasite should 

 write up the story for the benefit of other communities. This one job 

 might be worth the total cost of the public schools in some communities. 



Hookworm disease, uncinariasis — 

 Uncinaria americana. It only remains to 

 add a word as to life history and mode 

 of infection. The adult worms live in 

 the small intestine, where they gnaw 

 holes in the lining membranes and 

 suck blood. Besides this the patient is 

 likely to bleed liadly from the wounds. 

 How long the adults may live in the 

 intestine, if the case is not treated and 

 no new infection occurs, is stated by 

 Stiles to be certainly six and a half 

 years and probably from ten to twelve 

 years. A\^ith this rich food supply, 

 eggs are })roduced in great numbers. 

 These hatch in about twenty-four hours 

 and feed and grow in the soil for about 

 five days. The microscopic embryos 

 may then be swallowed with polluted 

 foods or water (carried to foods espe- 

 cially by flies), or, on coming in contact 

 with the skin, most commonly of bare 

 feet, they bore in, causing "ground 

 itch," and make their way to their 

 final destination in the intestine. Stiles 

 says that the embryos live in the soil 

 " probably eight to twelve months." 



This is a sectional problem, and 

 every school (especially every high 

 school) in the South should have in its 

 school library the latest information ob- 

 tainable from the Rockefeller Sanitary Commission for the Eradication 

 of Hookworm Disease,^ and also the bulletins of the United States Bureau 

 of Public Education, notably Bulletin No. 20, " The Rural School and 

 Hookworm Disease," Washington, D.C, 1014. Knowledge is growing 

 so fast that the latest and best should be secured from year to year. 



1 Address, Washington, D.C. 



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Fig . 120. Trichina worm embry( > 



cysts in human muscle and adult. 



female from intestinal wall 



After Leuckart 



