But this process is much too slow for modern days. Machines called microtomes (_i.e._ cutters of small parts) have been invented, and of these there are several kinds--in all, however, the razor is worked by machine and not by hand, so as to secure steadiness and a uniform thinness of the sections. The old microtomes threw off each section separately; but now matters are so arranged that the wax of each section adheres to that of the next, and the whole series of sections forms a continuous ribbon of thin wax. A large specimen, affording a number of sections, thus results in a ribbon of considerable length. Further processes are now required to fit the sections for the microscope. The ribbon must be divided into successive pieces of a length determined by that of the slides to be used. These are mounted in order on the slides, steps are taken to melt away the wax from the sections, the latter are covered with Canada Balsam surmounted by a glass cover slip, and left for some time to dry. After this they are ready for examination, and it is only now that the work really begins. All that has gone before is mere handicraft; it is time now for science to be called into play. [Illustration: FIG. 47.--Sections of Embryo Chick, eight days old. A slide mounted for microscopic examination, showing sections arranged in ribbons.] The sections must be compared with others of the same kind which have been cut before. Do they entirely resemble these, or is there a difference somewhere? Happy the man who finds that his sections represent a fresh stage, perhaps older or younger than any that has been seen before in the history of the particular animal which is under investigation. Happier still the man who has succeeded in getting hold of an animal which has not been described before. He will make haste to write a full description of it, illustrated by drawings; to found a new theory on it, if that can possibly be done; and to publish it to the world. It will go all over the globe. To every country in Europe; to the centres of learning in the United States; to universities in New Zealand and Australia, and our other colonies; and perhaps even to "Far Japan."