REPORT OF THE SOCIETY 107 



length, while the females are nearly one-half inch. They produce enornious 

 numbers of eggs which, like those of the eelworm, are passed with the feces, 

 and are scattered everywhere. They are taken up by children and others in 

 the same way as those of the eelworm. Eggs of both species may be trans- 

 ported by flies, as well as by more direct contamination to food, candies and 

 toys, and thus be swallowed. 



In the instances so far cited the parasite gains access to its human host 

 by a passive transfer, i.e., the eggs are accidently scattered and are taken 

 up with food or drink. In the case of a number of nematodes the transfer 

 is an active one, the young worm burrowing into its final host. A notable 

 example of this method is afforded by the hookworm, so prevalent in the 

 southern United States. Infested individuals scatter the eggs by soil pollu- 

 tion, they develop into larval forms, and these actively attack new individ- 

 uals, boring into the skin of the feet or other parts exposed, and finally reach- 

 ing the alimentary canal, where they become sexually mature, and a further 

 source of soil contamination. 



We have cited but a few typical illustrations of life histories of internal 

 parasites of man and animals. These examples might be many times multi- 

 plied but enough has been said to show that such parasites constitute a dis- 

 tinct menace to the health of man and his animals, and that they are propa- 

 gated and spread by general* insanitary conditions. The one basic prin- 

 ciple on which the control of parasites rests is cleanliness — cleanliness of the 

 individual, cleanliness of his surroundings, cleanliness of the community, 

 and cleanliness of the more reinote sources of food supply. 



Parasitic infestation in many cases ineans nothing more or less than 

 the swallowing of human excrement with accompanying eggs of parasites 

 which are able to develop without passing through an intermediate host. 

 We have seen that the contaminated matter may be conveyed directly from 

 soiled fingers, or food handled by such fingers, or that it may be taken in 

 with food or water which has been more indirectly contaminated. This is 

 not a pleasant thought but it is essential that it be realized if progress is to be 

 made in the control of diseases of this type. 



Thus a prime consideration in rural, as in urban, sanitation is the proper 

 disposal of human excreta. All too often this need is ignored and in the vast 

 majority of cases the best that is attempted merely serves to render the 

 waste less directly offensive. Conditions such as are shown in figures 8 and 

 9, from a publication by Dr. C. W. Stiles, 1910, are not in the slightest degree 

 exaggerated, but can be matched in any community. Yet, short of no 

 arrangements whatever, it would be impossible to devise any more efficient 

 way for the natural spread of intestinal diseases and parasites. 



