The time may be considered opportune for bringing forward this subject in that the near approach of the publication of the completely classified results of the census of 1901 will cause the attention of many Medical Officers of Health to be directed to the possibility and desirability of using the census data for working out Life-Tables for their respective districts, and doubtless the construction of many more local Life-Tables will be contemplated than was the case after the census of 1891.

That Cattle-Plague (Rinderpest) is one of the most fatal and contagious maladies of cattle needs no further demonstration. The disease appears to be widely distributed in China, and is endemic in the hinterlands of Shanghai, Chinkiang, Hongkong, Pekin, Tientsin, and Chefoo.

The observations here recorded were made, for the most part, during a journey through Upper Palestine and Lower Syria, in June and July, 1901. The country traversed is indicated upon the accompanying map. Its character is so well known as not to need detailed description, being for the most part very hilly and rocky or level plain.

Resting Position of the Imago.—Geographical Distribution of the Species.—Habitat.—Modes of Dissemination and Migratory Flights.—hibernation of the Imago.—Longevity.—Oviposition, and the Influence of Food thereon.—Parthenogenesis.—Numerical Proportion of Sexes.—Number of Generations during a season.—Food.—Influence of Heat, Cold, Light, Colour, and Sound.—Sense of Smell and Taste.

The theories of Ehrlich on the Substances and Mechanisms concerned in the production of Immunity have opened up a very wide field for speculation and research. His view on the formation of the Antitoxins forms the most satisfactory and useful hypothesis which has been produced upon this subject, and is constantly receiving fresh support from the accumulating evidence of numerous observers. But of the more recent developments of his theories as applied to antimicrobic agencies some of the details appear to be at present insufficiently established. With certain of these details it is here proposed to deal.