100 TROPICAL MEDICINE AND HYGIENE 



In some common forms of dyspepsia it never reaches 

 this degree of acidity. When water is taken alone little 

 or no acid is secreted in the stomach and the water does 

 not remain long in that viscus. With a purely vegetable 

 diet little acid is formed. The argument a's to the 0*2 per 

 cent, acid is not conclusive as excluding the possibility of 

 living larvae passing through the stomach at some time or 

 other even in healthy persons. 



Whether or not infection by the mouth is the com- 

 monest method of infection to be considered may be 

 doubted. There are some etiological factors in favour 

 of the view that this is the important and ordinary method 

 in which large infections are acquired. The incidence of 

 the disease amongst the different races working on the 

 same land varies greatly, though both are doing the same 

 class of work, and both work barefooted. The one race, 

 such as the Indians, eat rice mixed by hand and finely 

 divided, so that there are great possibilities of such food 

 being contaminated with particles of earth on the un- 

 washed hands. Another race, such as the Fijians, or 

 Melanesians, though holding the food in their hands, eat 

 solid masses of food, such as the cooked tubers of yam 

 or of the Arum esculatum, and in these solid masses, 

 where the outside only can be contaminated, the chances 

 of the introduction of ankylostome larvae are distinctly 

 less. Members of such groups may harbour a few 

 ankylostomes, large numbers are but rarely present. 

 "Water itch' 3 is common in many districts where ankylo- 

 stomiasis is rare, and rarely seen in others where it is 

 prevalent. 



Prophylaxis. As the recognition of the eggs is a simple 

 matter it is important that in any district where the 

 infection is prevalent the general public should be properly 

 instructed as to the causation of the infection and its 

 effects. With a, naturally, intelligent population much 

 can be done at schools and by public lectures and 

 demonstrations, and Rockefeller's Commission in the 

 Southern States of America has proved the value of 



