MICROSCOPIC WONDERS 11 



craftsman able to build a case from chemical matter held in 

 solution in water cases of most gorgeous designs, some even 

 able to move by what means no one knows such is the 

 diatom, one of the most interesting inhabitants of every 

 pond and stream. The owner of a microscope may spend 

 his life studying the cases of these minute plants, for their 

 numbers are legion, and the patterns revealed by the micro- 

 scope become most interesting, and more beautiful the higher 

 the power of the lenses used. 



Each minute plant, the largest being ^\jth of an inch in 

 diameter (the average vary from y^ of an inch to less), builds 

 its siliceous case in the form of a pill-box and lid. And in the 

 security between the two valves (frustules) the tiny plant 

 lives a perfectly secure life for the cases are so hard that no 

 crushing can damage them. And these strongly-built cases 

 are deeply engraved, so as to form most exquisite designs, 

 unequalled by anything man has devised. 



And when one considers that the owner and maker of the 

 case is firstly ^^ of an inch in diameter, secondly a single 

 cell, and lastly a plant, one wonders at the marvels of the 

 universe, and how wonderful even the most insignificant 

 object may be. 



Apart from how the plant should be able to make the case, 

 the question arises, How is it that each little cell of the same 

 kind should build a case similar in every detail to others of 

 the same family ? Thus we have the round case of the Heleo- 

 pelta, the triangular cases of Triceratium, the boat-shaped of 

 Naviculae, and countless more. 



The diatom, like everything else that lives, has one main 

 object in life, and that is that its species will survive. 



Diatoms increase as follows : the pill-box forms a new lid, 

 and the lid a new box, but the new part is not so large as the 

 former, and hence the diatom becomes smaller and smaller 

 as the age increases. But a time comes when this minute 

 organism realises that there is even a limit to smallness, and 

 then, guided by some uncommon sense (for we can hardly place 

 reasoning power in one cell, and that a plant), it changes its 

 methods of reproducing, and joining on to another of its 

 species, it becomes surrounded by jelly. Then the two dia- 

 toms, by a process into which we will not inquire, fuse 

 together to form an individual of sensible proportions. 



Some diatoms live singly, and, as before mentioned, can move 

 about at their " own free will." It must be left to the owner 

 of the microscope to feel the sensation occasioned by the move- 

 ments of these extraordinary plants. Suffice to say, that 



