OF THE DIATOMACE.E. 11 



CHAPTER II. 



OF THE DIATOMACE.E. 



These tiny members of the great vegetable kingdom are 

 generally the first to engage the attention of the collector, 

 for their distribution is almost boundless. I suppose there 

 Js scarcely a single piece of water anywhere which does 

 not contain at least some individuals of the commoner 

 species. They are to be found alike in the lake that 

 crowns the mountain-top, and the swamps and peat -beds 

 which fill the lowest valley ; in the water-course employed 

 to irrigate the meadows ; in the broad ocean and the 

 shallow puddle left by the overflowing of a ditch. The 

 brackish water, where the tidal river meets the sea ; salt- 

 works and salt-pits ; even inland lakes, which have a trace 

 of salt in them — each affords a rich variety of characteristic 

 Diatomaceae, varying according to the chemical quality of 

 the water.* They are to be frequently found also on rocks 

 and masses of stone, damp from overhanging trees, or from 

 the constant 'trickling of water. There they nestle among 

 the tufts of moss, or the layers of Oscillatorise ; or, in 

 company with other minute Algae, form a slimy mass of a 

 brown or olive green colour on the face of the bare rock. 

 Never let the collector pass by a spot of this description 

 without giving it a close examination. He will be often 

 rewarded with, some of the rarest and most lovely species. 



* It is quite astonishing what a slight infusion of salt suffices to 

 fix the character of the Diatomaceae. For example's sake I may 

 mention a lake in Hungary, and some pieces of water in Southern 

 Moravia, which contain an inappreciable quantity of salt, neverthe- 

 less the Diatomaceous forms answer exactly to those usually found 

 in brackish water. — J. K. 



