218 THE MICROSCOPE. [November, 



beautiful ; but many minds of a scientific turn refuse to become 

 interested in things not beautiful ; this is why the devotion to the 

 study of the diatom never surfeits or becomes irksome ; hence, 

 with some show of truth, we might paraphrase a popular saying, 

 " Once a diatomist, always a diatomist." 



Thirdly, the study of the Diatomacese from merely an observa- 

 tional point of view, whether in relation to their place in nature, 

 what role their creation was intended to fill in the economy of 

 nature or of earth-building, and their biological functions in life, 

 is capable of drawing forth the highest and best efforts of mental 

 genius, erudition, and the power of the judicial and critical qual- 

 ities in bright minds, in dealing with the numerous problems 

 suggested by repeated and lengthy association with their investi- 

 gation. A field of human effort is here offered well worthy of 

 capable minds, whose deductions may be grand enough to stand 

 as a trinity with the genius that points out the position of invisi- 

 ble perturbing planets in space, or those whose decisions go on 

 record as the final and unalterable disposition of questions as be- 

 tween right and wrong. 



The latter two fields of genius appear to be the conceded at- 

 tributes of many minds, the outcome of the total evolution of all 

 past advances made in erudition and civilization. Why, then, 

 should there not be a third character of talent, equal to the former 

 two, to deal with the co-ordinate problems of geology, palaeon- 

 tology, and biology ? These latter three sciences are invariably in- 

 vaded or trended upon by the diatomist, even though he may have 

 but the fame of an amateur. The above outline brings us to the 

 scope of action of the diatomist. His field of operations is catered 

 to by and is coextensive with the entire physical globe, and in 

 its atmosphere, as well as in its ocean depths, the rocky strata 

 composing its crust, penetrated for thousands of feet, is within his 

 horizon. When one looks back retrospectively on the colossal 

 and lengthy labors of Ehrenberg, condensed in his " Mikrogeo- 

 logie " (1856) ,utilizingtherein nearly every possible means within 

 the reach of man to bring to light what he could, those who now 

 live can look with deep admiration on this genius of the past, who 

 proved thus early the comprehensiveness of this branch of science ; 

 but the later and more recent activity in this line of research has 

 enormously increased our knowledge of the occurrence and dis- 

 tribution of the Diatomacese in the liquid and solid component 

 elements of the earth. To appreciate the available resources 

 within reach of the diatomist it is only necessary to peruse the 

 trade catalogues of two of the leading European commercial pre- 

 paratcurs. In these we have a tabulation, both by mineral family 

 groups and by their geographical distribution, showing varieties 

 of material derived from localities nearly as widely separated as 

 from North pole to South pole, from tropical America to tropical 



