The photographs introduced were taken under my direction in Manila in 1912, 1913 and 1914. Some of them show the character of the house construction in Tondo District, Manila, where plague flourished in 1913. Others illustrate methods of rat-proofing bamboo timbers in houses of light material. These end openings were either closed by introducing cement or by placing tight-fitting tin cans over the ends of the bamboo rafters. There are many interesting memoranda, gathered and made in connection with our antiplague work in Manila, especially concerning the location and construction of rat nests found by our laborers; the materials used and the fabrication of the nests. Memoranda giving details of rat catching and rat-proofing are also presented and notes showing the location of dead rats found in relation to dead human bodies of plague victims. Notes concerning cases of multiple house infection are also presented as being of possible interest. The Javan studies in 1911 and 1912 establish the fact that it is possible to form a fair judgment as to the length of time a rat has been dead, up to ten or twelve days, from the condition and appearance of the rat cadaver, both as to decomposition and drying. A series of 50 rats was studied. It is to be understood that the conditions under which these observations were made were tropical conditions. They would be fairly comparable with summer conditions in America, but should not be followed too closely at other seasons of the year. In my own experience I have observed that ants are likely to attack the cadaver early and to obscure the deductions by their destruction of the body. [Illustration: PROGRESSIVE POST-MORTEM CHANGES IN RAT CADAVERS. THE NUMBERS INDICATE THE NUMBER OF DAYS AFTER DEATH] Days after death Appearance First to third day Distention of the abdomen, increasing. Second to third day Loosening of hair by gentle pulling. Third to fourth day Loosening of the epidermis by gentle pulling. Third to fifth day Perforation of abdominal wall with collapse and disappearance of distention. This perforation may result from bursting of abdominal wall, or through anus, vulva or thorax. Fourth to sixth day Moist shrinking of the body. Swarming of maggots. Spontaneous shedding of tufts of hair. Fifth to eighth day Drying of body. Eighth to twelfth day Complete dryness and rigidity. Photograph (after _Publications of the Civil Medical Service in Netherlands, India_) shows the progressive postmortem changes in rat cadavers, the numbers indicating the number of days after death.