PLANT LIFE IN PONDS & STREAMS 



ing matter of higher plants. In shape they may be 

 rod-shaped, crescent-shaped, circular, wedge-shaped, 

 oblong or oval. Some float about freely in the 

 water, some are attached to supports by means of 

 stalks. Some lead a solitary life and others dwell 

 together in colonies. One feature they have in com- 

 mon, a curious flinty cell wall, and this is their most 

 interesting point to the microscopist. This natural 

 armour is in two parts which fit one within the other 

 like the two halves of a Japanese basket. All man- 

 ner of beautiful sculpturing marks these beautiful 

 frustules as they are called; in some cases they are 

 perforated and the living matter from within passes 

 through the pores and forms a jelly-like covering 

 for the little plant. 



We must make a point of collecting all the 

 Diatoms we can find, for they are always interest- 

 ing; moreover, they are easily preserved and made 

 into permanent slides, for the little plants may be 

 boiled in acid to destroy their living parts and the| 

 frustules will survive the boiling undamaged. \ 



One might wonder how such humble plants, sur- 

 rounded as they are with flinty walls, could in- 

 crease. They frequently do so in a simple manner. 

 The living matter of which the plant is composed! 

 pushes the frustules apart and divides across the 

 middle. The result of this event is the format ior 

 of two plants, each with a single frustule. In t 

 very short time each plant grows a new frustule 

 but it is always much smaller than the one wit! 

 which it started. 



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