63 
Calandruccio) ; United States (specimens in the B. A. I. Coll., U. S. 
Dept, of AgT., collected in Maryland and the District of Columbia); 
Brazil (Lutz, 1894). 
The fiofures seem to show that a rather warm and moist climate is 
especial!}" favorable to the development of cases of Ilymenoleph nana. 
As would be expected upon the assumption that the forms in man and 
in the rat are the same species, the statistics indicate a certain degree 
of coincidence in the occurrence and frequency of TL nanam man and 
in the rat for any locality, modified, it is true, by other factors, such 
as the hygienic conditions of the community, the habits and customs 
(personal hygiene, character of food) of the inhabitants, etc. In gen- 
eral its distribution may be considered cosmopolitan, like that of its 
hosts, but more restricted by certain conditions, among which are, 
perhaps, climate and moisture. 
SITUATION IN THE INTESTINE. 
The results of a number of autopsies show that the portion of the 
intestine infested is a greater or less part of the ileum, especially its 
upper two-thirds or three-fourths. 
NUMBER OF SPECIMENS PRESENT. 
The number of specimens of II. nana present in the various cases 
has ranged from 1 to several thousand. In one case, 1 specimen only 
was found at the autopsy; 2 specimens were passed in one case; 20 
were present in one case; 30 to 40, 1 case; 50, 1 case; 50 to 80, 1 case; 
between 100 and 200, 2 cases; from 200 to 400, 4 cases; 600 to TOO, 1 
case; 1,000, 1 case; 1,400, 1 case; 2,000, 1 case; in 5 cases in which no 
figures were given there were said to be few; in T cases a very large 
number or several thousand. 
OTHER PARASITES PRESENT. 
Multiple infection occurred in 27 cases. Oxyuris vermicularis was 
present 12 times, Trichuris trichiura 19 times, Ascaris liunbricoides 16 
times, Agchylostoma diiodenale 5 times, Uncinaria araericana once, 
Tdenia saginata 2 times, Tdenia solium once, encysted flagellates once, 
larval nematodes [? Strongyloides stercoralis\ once. They were asso- 
ciated together with H. nana as follows: 
Trichuris., 6 cases; Ascaris, 3 cases; Oxyuris, 2 cases; Agchylostoma 
duodenale, 1 case; Uncinaria americana, 1 case; Tdenia saginata, 2 
cases; Oxyuris and Trichuris, 1 case; Oxyuris and Tdenia solium, 1 
case; Oxyuris and larval nematodes [? Strong yloides\, 1 case; Oxyuris, 
Trichuris, and Ascaris, 6 cases; Trichuris and Ascaris, 2 cases; 
Trichuris, Ascaris, 2 ix\di encysted flagellates, 1 case; Trichuris, Ascaris, 
and Agchylostoma duodenale, 2 cases; Ascaris and Agchylostoma 
duodenal e, 1 case; Oxyuris, Trichuris, Ascaris, and Agchylostoma. 
duodenale, 1 case. 
