230 
Distribution of Hookworms 
thoroughly familiar with the two races, I was at times unable to tell which 
of two sunburnt boys was the Malay and which the Chinese. 
Yet close as the physical resemblances such as physiognomy, physique 
and cranial indices are, the helminthological testimony indicates that the 
Malays as a whole are no recent migrant stock from Southern China. 
The Malays are not Chinese who have moved southward towards the 
equator and mixed with a dark skinned race, for the worm formula of the 
Malays is distinct from that of the Chinese. If the Chinese had migrated into 
Indonesia in hordes the ancylostome index of the Malays would approach 
that of the Chinese but this it does not do. 
Some Malays may have moved northward and added their complement 
of Necator to an ancylostome-bearing Chinese stock, for the Chinese of South 
China to-day carry large numbers of Necator with their ancylostomes. 
The presence of A. duodenale in mid and East Java, Madura, Lombok 
and Timor is not due to the presence of the relatively few Chinese coolies, 
traders or shopkeepers there, for the native population greatly outnumbers 
the Chinese. As a result we see the Chinese that are born in Java taking 
on the native index. 
On the other hand where large numbers of A1 duodenale carriers are 
present, as among the North Indians in Fiji, they are perceptibly infecting 
the native Fijians, just as we may suppose the Hindus or Burmese may have 
infected the Javanese of mid-Java centuries ago. 
A small group of Japanese women, four in number, who had lived in the 
Federated Malay States three years and under were found to harbour 61 hook¬ 
worms of which 19 were A. duodenale , giving an ancylostome index of 31-1. 
The index of the Japanese therefore resembles that of the Chinese and North 
Indians and is in marked contrast with the primitive index of people south 
of 20° N. latitude, that is, the Tamils, Malabaris and Malays. 
Thus we see that there is a solid zone lying to the north within which the 
people have high ancylostome indices. It is from people in this more northerly 
zone that A. duodenale was introduced into mid and East Java and neigh¬ 
bouring islands. 
South Indians. 
Tamils, Malabaris and other Davidian natives of Southern India entering 
the Port Swettenham Quarantine Station were found to possess a uniformly 
low ancylostome index. 
A series of treatments were carried out by Hacker and Barber on South 
Indian coolies, Tamils and Malabaris at Port Swettenham Quarantine Station. 
From three squads, 31 persons, 4363 hookworms were obtained, 89 of 
which were A. duodenale giving an ancylostome index of 2-0. 
This low ancylostome index among South Indians was encountered with 
great uniformity and serves to differentiate the North from the South Indians. 
Twenty-five Malabaris that had lived in the Federated Malay States but 
