on which are mounted four thousand diatoms, with which there is a printed catalogue. This single plate is the result of four years of continued labor, and the price he fixes for it is twenty thousand marks, or about five thousand dollars. I inquired if there was any probability of the owner selling such an expensive collection, and he said very quickly: "Oh, yes! Some rich English or American gentleman will probably purchase it; no German ever will." According to some of the latest systematic
Fig. 8. Microscopic View of Richmond Infusorial Earth. (By Ehrenberg.)
authorities, there are about eight thousand different species so this plate may be considered as representing half of the known species.
It may be doubtful whether this story will help relieve the embarrassment of those who do not exactly understand what a diatom is. It serves to show, however, that very few people do know all about it; and this, together with the thought that it is considered of sufficient importance to warrant spending years of patient labor over it, will surely prove a consolation to those who have been puzzling over the meaning of the word.
