1892.] MICKOSCOPICAL JOURNAL. 251 



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

 trade catalogues of two of the leading European commercial frc- 

 paratciirs. 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 

 Africa ; but these lists suggest little of their geological association. 

 We have them from summits and slopes of mountains thousands 

 effect in height ; from the oceans thousands of fathoms in depth ; 

 from bituminous strata, marly strata, peat strata ; from intra and 

 post glacial strata ; from subplutonic strata ; from lignite strata ; 

 from American Miocene clay strata, penetrated for a thousand 

 feet in depth ; from drifted specimens from Pacific Ocean bottom 

 stranded on its west coast ; from vast stratified areas in Missis- 

 sippi and Alabama ; from the rocky strata of the islands of the 

 Atlantic and Pacific Oceans ; from vast beds of extinct lacustrine 

 areas ; from subpeat areas ; from the muds and humus of swamps, 

 marshes, creeks, bayous, rivers, bays, and seas, and from the ooze 

 of ocean depths; from saline and thermal springs, and from the 

 aquatic flora of all waters ; again, inclosed in altered and petri- 

 fied strata ; from strata in New Zealand altered and metamor- 

 phosed by intrusive igneous action or by volcanic action ; from 

 the guano islands of the South Pacific Ocean, and inland pelagic' 

 desert plateaus of Chili and Peru ; from the extinct lake deposits 

 of the Southern river drift or Diluvium period, and the Tertiary 

 sedimentary rocks of the Mexican Gulf coast of the United States ; 

 with recurring announcements of the finding of new deposits ; 

 thus continually furnishing material for unceasing interest in their 

 study. But, perhaps, diatomology will never complete its ideal 

 cycle until, in addition to the listing and naming of new species and 

 noting localities of occurrence, the geological relations of the de- 

 posits as to period, association, and sequence of strata, as well as 

 a comparative study of deposit contents, shall be worked out by 

 the larger methods of the geologist as applied to all other rock 

 formations, aided by graphic and pictorial illustrations of the 

 strata and characteristic natural scenery in situ^ together with a 

 discussion of the attendant phenomena of deposition, with the 

 speculative deductions and inferences to be derived therefrom, 

 the economic relations and value of these deposits to the arts, and 

 all these data digested, correlated, and generalized, shall the full 

 capabilities, impressiveness, and grandeur of this entrancing 

 science be put upon the pedestal destined for it in the arcana of 

 nature. 



We have so far but scattered, imperfect, and disconnected 

 gleams of the store of treasures yet to be segregated in the future 

 into one grand whole for the intellectual gratification of pos- 

 terity's millions. Diatomology comprises within its fold an army 

 of independent investigators whose efforts are largely absorbed 

 in working out and elucidating the many-sidedness of the science ; 



