﻿NECATOR AMERICANUS IN THE PHILIPPINES. 335 



to form the basis for the supposition that a new species of Necator had 

 been found in the Philippine Islands. 



About the time this conclusion had been reached and an effort had 

 been made to describe this supposedly new variety of Uncinaria, it ap- 

 peared that others were finding species of Necator differing from Necator 

 americanus. 



Stephens 7 thinks that Necator americanus may be only one of many 

 species which exist in different parts of the world. He has found va- 

 rieties of Necator differing from Necator americanus in material collected 

 in Burma and Assam. Loos s of Cairo confirmed Stephens's statement 

 and identified at least three different species in the material which the 

 latter had collected. It is not known upon what characteristics Stephens 

 bases his differentiation as no specimens have been described by him. 



In January, 1907, through the kindness of Lieut. P. E. Garrison, 

 United States Navy, medical zoologist at the Bureau of Science, an 

 opportunity was given to compare the Uncinaria I had obtained with 

 type specimens of Necator americanus which he had procured in Wash- 

 ington from Stiles. They were found to be similar. 



After quoting the description given by Stiles for Necator americanus 

 I will attempt to demonstrate by means of drawings and photomicro- 

 graphs the characteristics of the Uncinaria found here. 



The New World hookworm of man, Uncinaria americana Stiles, 1902. 



Specific diagnosis. — Uncinaria: Body cylindrical, somewhat attenuated ante- 

 riorly. Buccal capsule with a ventral pair of prominent semilunar plates or lips, 

 similar to U. stenocephala, and a dorsal pair of slightly developed lips of the same 

 nature; dorsal conical median tooth projects prominently into the buccal cavity, 

 similar to Monodontus ; one pair of dorsal and one pair of ventral submedian lancets 

 deep in buccal capsule. Male, 7 to 9 millimeters long; caudal bursa with short, 

 dorsomedian lobe, which often appears as if it were divided into two lobes, and with 

 prominent lateral lobes united ventrally by an indistinct ventral lobe; common 

 base of dorsal and dorsolateral rays very short; dorsal ray divided to its base, 

 its two branches being prominently divergent and their tips being bipartite ; spicules 

 long and slender. Female, 9 to 11 millimeters long; vulva in anterior half of the 

 body, but near equator. Eggs, ellipsoid, 04 to 70 /u. long by 30 to 40 fj. broad, 

 in some cases partially segmented in utero, in other (rare) cases containing a fully 

 developed embryo when oviposited. 



Habitat. — Small intestine of man (Homo sapiens) in America (determined to 

 date (1902) for Virginia, North and South Carolina, Georgia, Florida, Alabama, 

 Texas, Porto Rico, Cuba, and Brazil ) . 



'Indian Med. Gaz. (1900), 41, 398. 



''Ibid.. 



"The single male specimen oi'Necator americanus which was given me had been 

 mounted for some time, and as a result of the pressure of the cover glass the 

 specimen is flattened and can not be placed in as favorable position for demon- 

 strating the structures in question as some of the fresh ones from the Philip- 

 pines. 



