of Ocean-weeds 



which Is a kind of box, consistincr of two halves 

 or ''frustules," neatly joined together by a ring 

 or girdle. 



Diatoms increase in numbers, like many of the 

 Foraminifera, by simply dividing into two. 

 When the living cell thus parts, each half takes 

 as its share one side of the box, and each then 

 makes another side, or *' frustule," to complete 

 itself. For this operation, the tiny ring or hoop 

 doubles into a pair of hoops, one of which clings 

 to each half of the case. 



Perhaps in all the world no greater marvels 

 are to be seen than these extraordinary minute 

 veo^etable-cases. 



Minute! Yes. A mass of millions upon 

 millions, held together, may be perceived and 

 felt. But let a light scattering of them be 

 dropped upon a slip of glass in broad daylight, 

 and let a man of keen eyesight set himself to 

 examine them. He will see— nothing ! Not 

 even an appearance of delicate dust. The 

 diatoms are to him as if they did not exist. 



Then let him put that fine scattering under 

 a good microscope, changing lens after lens, to 

 higher powers. A world of beauty, of finish, of 

 originality, of unbounded variety in construction, 

 will open out before him. 



155 



