﻿20 The Philippine Journal of Science 1914 



after the disease made its appearance in Manila, large numbers 

 of rats were caught along the water front and near the wharves, 

 but none of them were found to be plague infected. The rat- 

 proof piers at which foreign vessels lie have been all that their 

 description implies; they have remained rat free. On account 

 of the fact that the first cases occurred among permanent resi- 

 dents and among persons who had not been out of Manila in many- 

 months and who did not associate with people who worked along 

 the water front or with persons who had recently been in a 

 plague-infected country, it seems reasonable to infer that the 

 disease was not introduced by human beings. As no infection 

 could be found among the rats of the water front and especially 

 since the wharves remained free from rats, it does not seem 

 probable that infected rats could have come from a ship by means 

 of gangways, cargo chutes, lines, or by other direct means. All 

 vessels that ply in Philippine waters are fumigated at least 

 twice annually; vessels from ports that are suspected of being 

 infected with plague are fumigated every other trip ; and vessels 

 that carry rice or other food supplies which are especially liable 

 to carry rats are fumigated every trip; so that the liability of 

 plague rats coming ashore directly from ships is extremely im- 

 probable, and moreover none of the rats found in such ships in 

 the course of the fumigation work showed any evidence of plague. 



There does remain, however, the very strong probability that 

 plague rats may have been introduced into Manila in cargo and 

 may have made their escape therefrom after it was delivered in 

 the city. This is possible in view of the enormous quantities of 

 food supplies and other cargo that come directly from plague- 

 infected centers in China and Japan. For instance, every week 

 there are literally thousands of baskets or crates of eggs, garlic, 

 onions, and similar foodstuffs, among which rats can easily 

 take refuge, that come from places like Canton and Amoy within 

 a period of five days. It is well known that plague has existed 

 in Canton, for instance, almost continuously during the past ten 

 years, and it is not improbable that plague rats might have been 

 introduced into the Philippines from that port. Large quantities 

 of cargo arrive from Japan as, for instance, glass- and china- 

 ware, bottles, and other things which are packed in hay and 

 straw. Among these a rat might easily have been brought into 

 the Islands. 



In a case of human plague which occurred at 508 Calle Mag- 

 dalena, bedbugs were found on the petate upon which the man 



