With a view to ascertain as far as possible the minute changes that occur in the cells of the mucous membrane of the stomach during, and after, activity, I procured from England towards the end of winter a number of newts (Triton cristatus).

When they arrived they were very emaciated, and, indeed, in a starved condition, having no doubt but recently awakened from their winter sleep; they appeared, however, quite healthy, and swam well when placed in water, and took and retained food when given to them in the form of lively worms.

These English newts were fed at the same time with the same weight of worm, and killed at intervals after the meal, one being sacrificed every twenty-four hours, to the end of the tenth day.

Such long intervals were allowed to elapse between each sample taken, because Langley (13) states that during winter in thin and emaciated animals that have been fasting for a considerable time the changes take place very slowly.

These constituted the first set of experiments.

In June of the same year I procured a large number of fine Triton cristatus from the Eft Pond in the Braid Hills near Edinburgh. They were in good condition and very lively.

When worms were given them, they ate them readily, and were hungry again in less than twenty hours. However, to make sure that the stomach was quite empty and in a resting condition, I allowed an interval of one hundred and fourteen hours to elapse after the first feeding, and then, selecting newts of about the same size and weight, fed them a second time, each receiving the same amount of healthy worm.