16 THE BEGINNINGS OF LIFE. 



standing water. If you examine some of this slime under the 

 microscope you will see that it consists of beautiful green 

 filaments, made up of cells placed end to end. The cells 

 reproduce by subdivision, but here again at times two filaments 

 (as far as we can see, in all respects identical) approach each 

 other. Canals are thrown across to opposite cells, and through 

 these canals the cells on one side pour their contents into the cells 

 on the other. The contents fuse together, and form a reddish 

 brown oval spore in each of the latter cells. Then the membrane 

 bursts and the spores are set free. These spores may be dried 

 up and carried by the wind to vast distances. At the return of 

 favourable conditions they acquire flagella, swim about actively 

 for a time, and then gradually develop into the usual filamentous 

 form. 



The next illustration shows another form of flagellate 

 animalcule, which is so large as to be just visible to the naked 

 eye. It is remarkable as being the cause of the phosphorescent 

 light which you often notice in the sea ; and it is therefore aptly 

 named noctiluca, or the night-light. It is a peach-shaped body, 

 and grooved something like a peach. From the groove proceeds 

 the whip-like filament or flagellum. In the interior of the cell 

 is seen the protoplasm, branching in all directions so as to form 

 a reticulated mass. The light has a beautiful greenish tinge, 

 and appears to originate from the marginal portion of the 

 protoplasm, and to be due to electric action.' When the noctilucae 

 are very numerous they give rise to streams or tracks of light 

 after any object moving through the water, a phenomenon which 

 suggested the fantastic imagery of Coleridge in the " Ancient 



Mariner" — 



Beyond the shadow of the ship 



I watched the water-snakes. 

 They moved in tracks of shining white, 

 And when they reared the eltish Hght 



Fell off in hoary flakes. 



The diagram now shown illustrates the beautiful slipper 

 animalcule, or paramoecium, as it is called scientifically, an 

 animakule common in ponds and standing water. As it darts 

 into the field of view we notice that it is surrounded with minute 

 quivering hair-like processes, known as cilia, which glisten like 

 spun glass. These cilia are the same thing as fiagella ; they are 

 prolongations of the protoplasm, but they are far more numerous 

 and delicate. We observe, too, in the protoplasm a groove or 



