dissolved particles which act upon the nerves of taste can be distinguished by man into four groups--sweet, sour, bitter, and saline. But no such classification of "smells" is possible. As a rule mankind confuses the "taste" of things with their accompanying "smell." The finer flavours of food and drink not included in the four classes of tastes are really due to odoriferous particles present in the food or drink, which act on the terminations of the olfactory nerves in the recesses of the nose, and excite no sensation through the nerves of taste. The part of the brain from which the nerves of smell arise is of relatively enormous size in the lower vertebrates--as much as one fifth of the volume of the entire brain in fishes--a fact which seems to indicate great importance for the sense of smell in those forms. Even in the mammals (the hairy, warm-blooded, young-suckling beasts) the size of the olfactory lobes of the brain and of the olfactory nerves, and the labyrinthine chambers of the nose on which the nerves are spread, is very large, as one may see by looking at a mammal's skull divided into right and left halves. And it seems immoderately large to us--to man--because, after all, so far as our conscious lives are concerned, the sense of smell has very small importance. Yet man has a very considerable set of olfactive chambers within the nostrils and has large olfactory nerves. Not rarely men and women are found who are absolutely devoid of the sense of smell, and the same thing occurs with domesticated cats and dogs. In these cases the olfactory lobes of the brain are imperfectly developed. It is found that men in this condition suffer but little inconvenience in consequence. We are able, through their statements, to ascertain what parts of the savoury qualities of food and drink belong to taste and what to smell. Such individuals do not perceive perfumes, the bouquet of wine, or the fragrance of tobacco, nor can they appreciate the artistic efforts of a good cook. But they are spared the pain of foul smells, and possibly in this way they may incur some danger in civilised life through not being able to detect the escape of sewer-gas or of coal-gas into a house, or the putrid condition of ice-stored fish, birds, and meat. A friend of my own, who is devoid of the sense of smell, inherited this defect from his father, and has transmitted it to some of his children. I was surprised to find in conversing with him how often I alluded to smells, either pleasant or unpleasant, when (as we had agreed he should) he would interrupt me and say that my remark had no meaning for him.