WHAT ARE DIATOMS? 



205 



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 Eng- 

 lish or American gentleman will probably purchase it ; no Ger- 

 man ever will." According to some of the latest systematic 







Fig. 8. Microscopic View of Richmond Infusorial Earth. (By Ehrenberg.j 



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. 



