of Bacterium termo, but on examination with a one-tenth inch objective showed that it also contained a comparatively small number of intensely active organisms—­one being discovered in about eight or ten drops of the sediment.  These measured 1-10,000 of an inch in length by 1-19,500 of an inch in breadth.  The fluid had originally been kept at a temperature of 90 deg. to 95 deg.  F., and it was noticed that, when placed upon a cold stage under the microscope, the movements of the organisms became, gradually slower, until at last they entirely ceased; the necessity, therefore, arose for the use of a warm stage, and the very ingenious contrivance by which a continuous and even temperature was maintained within the one-tenth of a degree was exhibited.  The greatest difficulty in the matter was, however, experienced in obtaining specimens for observation, in order to be able to trace them from their earliest to their latest stage.  The President then explained, by means of an admirable series of illustrations projected upon a screen by the oxyhydrogen lantern, the life history of the organism to which he had referred, exhibiting it first as a translucent, elliptic, spindle-shaped body, with six long and delicate flagella, the various positions in which the five specimens were drawn giving a very good idea of its peculiar porpoiselike movements.

The various positions which it assumed in making an attack upon a portion of decomposed matter were also shown, the movements quite fascinating the observer by their rhythmical character.  The supposed action of the flagella in the production of the movements observed was explained, distinct evidence being afforded of a remarkable spiral motion, at least of those behind.  The process of fission was illustrated in all its observed stages from the first appearance of a construction to that of final and complete separation, the whole being performed within the space of eight or nine minutes.  A description of the process of fusion from the simple contact of two organisms to their entire absorption into each other followed, as well as their transformation into a granular mass, which gradually decreased in size in consequence of the dropping of a train of granules in it wake as it moved across the field.  The development of these granules was traced from their minute semi-opaque and spherical form to that of the perfect flagellate organism first shown, the entire process being completed in about an hour.  Experiments as to their thermal death-point showed that, while the adults could not be killed by a temperature less than 146 deg.  F., the highest point endured by the germs was 190 deg.  F. Illustrations of a variety of other modes of fission discovered in previous researches on similar forms were given, showing the mode of multiple division and a similar process in the case of an organism contained in an investing envelope.  The President concluded his address, which was listened to throughout with the