18 
In 1843 Dubiiii, of Milan, Italy, dcscribod a hookworm as parasitic 
in man. Besides the caudal “hooks" (i. e., the “rays") of the male, 
Dubini’s parasite presented four hooks in the mouth. It presented 
further an anatomical character which is common to all hookworms, 
nameh^ the ventral surface of the an- 
terior end g’rows more rapid than the 
dorsal surface, so that the oral end is 
bent backward like a “hook,'' and the 
mouth thus occupies a dorsal position. 
Thus it is seen that the orio-inal char- 
acter which led to the vernacular name 
“ hookworm'’ was a misinterpretation; 
the second character of “ hooks'' (name- 
h% in the mouth), which has been pop- 
ularly but erroneously interpreted as 
responsible for the vernacular name 
“hookworm,'’ is not present in all spe- 
cies; the hooklike curvature of the head 
is usually but not always distinct. I 
propose, however, to retain the word “hookworm" as a vernacular name. 
It is not apparent that Dubini knew that Fradich had ])roposed the 
^'enus UnchiarUi^ and it is probably on this account that he proposed a 
new genus — A(/cIn/J(fsfotn(vh\ name — to contain the parasite {Agc/njln- 
Htonia (J}mdenalt) which he had found in man. 
For years it was supposed that this was the only species of hookworm 
found in man, but in Mav, lb02, I showed that in America we have a 
distinct species, which I named Unclnaria americana. 
Fig. 1. — Caudal bursa of a male strongyle 
{(ICsoj>/ia(jt)K(oma dental imi), to serve a.s 
diagram for the family: v. r.. ventral 
rays; v.I. /•., ventro-lateral rays; 1. r., lat- 
eral rays; d. 1. r., dorso-lateral rays; d. r., 
dorsjil rays. X y3. (After Sehneidcr, 
1S6G, p. 130.) 
ZOOLOGICAL POSITION OF THE PARASITES. 
The parasites which cause uncinariasis are worms belonging to the 
nematode faniilv Strongvlidtv. 
Family STKONGYLIDA]. 
Famii.y DIAGNOSIS. — NeiiKitoda: With laxly elontjate, cvlimlrical, rarely tilifonu. 
Mouth is probably always provided with six papilla*, of which the four siibmediaii 
are generally salient in form of nodules or conical ]>oints. In some ea.‘<es the mouth is 
in the axis of the body; in others it is turned dor.sally or veiitrally, and occasionally 
provideil with a ehitinous armature. Esophagus more or less swollen in posterior 
portion, but without forming in adults a distinct esophageal biilh. Male provided 
with a caudal bur.*ia, open or eloseil, entire or divide<l, and with oiu* or two spicules. 
Female with one or two ovaries; vulva aiit(*rior or posti*ri<*r of equatorial i>lane, m 
some eases near the anus. Eggs deposited during segmentati<»n, in some ease's 
containing embryo. 
Type gencs. — Strongiflus O. F. Mueller. 
The sexes are .separate and the digestive tract is compicti*. Charac- 
teristic for the family is the pre.sence, on the tail ot the mah*, ot an 
umbrella-like structure known as the caudal or “copulatorv Imrsa, ’ 
