intelligent but ignorant listener is to feel happy and is really to understand what is said and done for his instruction. A special difficulty also arises from the fact that the lecturer often feels himself called upon to address and to say something to those among the audience who already know a good deal about his subject, as well as to make things clear to those who are absolute novices. Some people have made this discussion the opportunity for attacking on the one hand the English language, and on the other the use of special names applied by men of science to special things and special processes. We cannot at once change the English language, even did we wish to do so. But the creation of special names to distinguish things not distinguished from one another in common speech is a necessity. It cannot be avoided. It is mere impatience and temper to call the names and terms which are necessary as counters of thought “jargon.” No doubt there may be in some lecturers and writers a tendency to excessive use of special terms and names, but the real trouble in the matter arises from the too rapid thrusting of a large number of such unfamiliar words upon an untrained audience. If new words are introduced in moderation they can be assimilated. They cannot be dispensed with altogether. A correspondent lately complained to me that I wrote of the minute creature which causes the sleeping sickness as a Trypanosome, whereas, had I called it “a blood-parasite” he would have known what I meant, and been able to follow my statement more easily. I am sorry to say that I cannot agree with him. There are many kinds of blood-parasites; there are the worms known as Filariæ, there are the vegetable microbes known as bacteria and bacilli and spirilla, and there are minute creatures of an animal nature called pyroplasma and trypanosoma (beside some others). These must be distinguished from one another if we are to understand anything about the causation of disease by microbes. It would be mere muddling and confusion to simply call them all by the same name, simply “blood parasite.” That would cause the same sort of confusion as would occur if the Smiths or Browns of our acquaintance had no Christian names by which we can separate each member of the class from the others and assign to him his own special qualities, opinions, and property. What some people call “scientific jargon” is assuredly not a thing to be proud of or to mouth with a sense of superiority. Nevertheless, it is absolutely necessary, and must be introduced gently and considerately to the stranger who can and will, if reasonably handled, appreciate the immeasurable advantage of having distinct words to signify distinct things. That, after all, is an elementary feature in all language. And just as the “jargon” of a game, a sport, or a profession has a fascination for those who use it, and forms a bond of union or special understanding between them,