ii4 HIDDEN BEAUTIES OF NATURE 



even amateurs can produce very good photo-micro- 

 graphs. You will observe that sunlight is not 

 necessary in all branches of photography. This is a 

 great advantage, because during long winter evenings 

 photographing microscopic objects becomes a well- 

 patronized occupation. 



* The photograph of our diatom is now placed in 

 the lantern, and we can make it appear eight, ten, or 

 twelve feet in diameter, so that you can now see the 

 multitude of lines and spaces and patterns I have 

 been describing and showing to you. All the lines 

 and possible perforations of this wonderful diatom 

 are enclosed "within the dimensions of a point" a 

 point too small to be recognised by the keen-sighted 

 watchmaker.' 



The next questions were, 'What are diatoms?' 

 1 Are there many of them ? ' c Besides drawing out 

 our admiration and making us to feel humble, of 

 what use are they in the great economy of Nature ? ' 



' Diatoms are microscopic aquatic plants, found in 

 all the fresh and salt waters of the globe that are 

 capable of sustaining life. They are generally of a 

 golden brown colour, and, probably owing to ciliary 

 action, they are able to move about. Cilia are ex- 

 tremely fine lashes, which cannot be seen unless with 

 extraordinary high powers. They prevail in all de- 

 partments of life. 



' Each diatom, in addition to its vegetable structure, 

 possesses a beautiful flinty box, having a lid, bottom, 

 and rim ornamented in the manner described. And 



