38 THE SIMPLEST FORMS OF LIFE 



Since the earlier chapters of the story of life have been 

 destroyed we have no direct knowledge of the forms that 

 immediately succeeded these simple forms. Many of them, 

 however, have survived to this day, so that we can arrange 

 them in an evolutionary series. We have thousands of 

 species of organisms that consist of a single cell, a single 

 particle of plasm. We have others that consist of a number 

 of cells loosely associated the beginning of the multi- 

 cellular animal. In a word, we have a fairly gradual series 

 of organisms leading up from the microbe to the shark-like 

 ancestors of man, large fishes with brain and excellent sense- 

 organs, that make their appearance at the close of the 

 Silurian period. From these onward the story of evolution 

 is clear enough. At what point does Sir Oliver Lodge's 

 spirit-world break in ? 



We may take the amoeba, which he seems to present as 

 an instance. It is unfortunate that he baffles the critic so 

 much by the vagueness of his indications. The amoeba is 

 a much larger particle of protoplasm. It is particularly 

 important for our purpose, because in it we find all the 

 vital functions in a rudimentary form. It splits into two, 

 like the simpler microbes, for reproduction ; but it has the 

 germ-stuff apart in a central nucleus. It absorbs food- 

 particles into its soft, slimy body at any point ; but it may 

 send out projections to wrap round the approaching 

 particle. Touch it with a needle, or put a drop of acid in 

 its bath, and it rolls into a ball. Remove the stimulus, and 

 it thrusts out its projections, and crawls along in search of 

 food. Here we have the fundamental functions of nutrition, 



