1R4- Biology in America 



now consists of a sack-like bladder filled with fluid, which has 

 griven this, and similar larvfe the name of "bladder-worm," 

 inside of which is the head in an inverted position like the 

 intunied finger of a glove. In the muscles the larva is sur- 

 rounded by a connective tissue sheath similar to that surround- 

 ing the Trichina larva already described. If a piece of 

 improperly cooked beef containing one of these larva? is eaten 

 by man, the "bladder-worm" loses its "bladder," turns its 

 "head" inside out, thus bringing it into the proper position 

 for a frontal attack on the intestine of its host, to which it 

 attaches itself by means of four "suckers" on its "head," 

 and now proceeds about its business of growing and produc- 

 ing ripe segments, which may in their turn infect another 

 beef. 



For the benefit of those who enjov a nice juicy piece of 

 rare beefsteak it may be said, that with the very efficient in- 

 spection service of the U. S. Bureau of Animal Industry the 

 occurrence of tapeworms in this country is decreasing, and 

 m(>at coming from an inspected slaughter house may be eaten 

 with impunity. This of course does not apply to meat 

 slaughtered by country butchers. 



Living in our Southern States is a community of people 

 cfdlrd with contempt by negroes and whites alike the "po'- 

 whites." They are a shiftless, lazy lot of "ne'er-do-wee's" 

 living in utter disregard of health or decency. Many of them 

 have never been to school, and those children who do go to 

 school stand from forty to ninety points lower on a scale of 

 one hundred in their ability to improve, than their comrades. 

 They are found in rural communities and the smaller towns 

 and villages wherever unsanitai-y living conditions occur. In 

 Porto Rico about ninety per cent of the poorer inhabitants 

 are of this type. "Slany of them are what are known as "dirt 

 eaters," rivaling even the traditional goat in their fondness 

 for paper, old rags, earth, lime, etc. For generations these 

 people have presented an insoluble problem to physician and 

 philanthropist alike. Was the cause of their condition hered- 

 itary ? Had some outcast from the slums of Europe escaped 

 to America with the early settlers and peopled the South with 

 his degenerate progeny? Or was the hard environment too 

 heavy a handicap for them to overcome ? AVas weak mental- 

 ity and feebleness of purpose to blame, or yet was the cause 

 a physical one, some insidious disease which inappreciably, 

 yet none the less certainly was sapping the energy, both men- 

 tal and physical of its victims ? 



The answer to these questions came to us indirectly from 

 Europe. In cutting the St. Gothard tunnel through the 

 Alps it was observed that many of the miners who were bare- 



