58 
With the foregoing premises in mind, it is important to determine 
how long the parasite in the intestine can live. Kegarding the Ameri- 
can hookworm, Uvc inaria americana. I can present the following 
data: Of children at the Charleston Orphan Asylum in whom I 
demonstrated the presence of Uncinaria americana microscopically, 
it may he noted that 8 children had been in the orphan asylum two 
years or less;*d children had been in the asylum between two and three 
years; 2 children had been in the asylum six years; 1 child had been 
in the asylum six years and seven months. 
1 have selected the Charleston Orphan Asylum as best fulfilling the 
conditions desired to illustrate the point at issue. The refined disci- 
pline. the scrupulous cleanliness, and the general hygienic conditions 
noticed are such that local infection is practically excluded. It must 
be admitted that some persons coming in from the country might 
possibly bring on their shoes a few embryos, but such a theoretical 
possibility is altogether too remote to explain the 15 cases found. 
For all practical purposes we are justified in assuming that the 
hookworms which these 15 children had in them when I saw them 
were the same individual worms which were in the children when the 
latter entered the asylum, and from the data obtained it is clear that 
hookworms of the species Uncinaria americana are capable of living 
six years and even six years and seven months. 
A sixteenth child (case of L. B.) examined showed a clear clinical 
historv of uncinariasis of long standing. Her condition at the time 
of entering the institution, as described to me by Dr. Huger, and her 
present complexion, eyes, stunted growth, and inferior mental develop- 
ment leave no practical doubt in my mind regarding the diagnosis. 
Xo normal eggs were found in her stools, despite the fact that 1 made 
25 slides. One slide showed a single abnormal egg which had evi- 
dentlv been dried and had clung to the slide after an examination in 
some other town. 1 do not know this gild's complete therapeutic his- 
toiy duidng the past twelve years, but from the absence of eggs in hei- 
st ools it is necessary to conclude either that the worms had been 
expelled by the drugs taken or else Uncinaria americana is not able 
to live twelve years. 
Ashford (see Stiles. 1902b. p. 210) mentions a case where a boy "had 
been the host of the worm for probably ten or fifteen years." but he 
does not state that during this time the patient was not exposed to 
further infection. 
The clinical importance of the length of the life of the parasite is 
self-evident. Suppose a physician in the North has an anemic patient, 
or a physician in the South has an anemic patient who lives in the city 
or in a clay district; it is not sufiicient to inquire whether he or she 
has recently been exposed to malaria, but inquiry should extend for 
eight or more years back in order to develop the fact whether she has 
