400 CELL INTELLIGENCE THE CAUSE OP EVOLUTION 



genetic relations of which to the egg cell are of peculiar 

 importance, will be evident from the following facts. In 

 many lower animals the egg cell remains in its original 

 naked condition until it is fertilized ; it requires no cover- 

 ing and is often indistinguishable from an amoeba. Like 

 the latter, these naked egg-cells can extend processes and 

 move about. In the sponges these active egg-cells creep 

 freely about as though they were independent amoeba, 

 even within the parent organism. In this condition they 

 were observed by earlier naturalists and were mistaken 

 for amoeba, living as parasitical intruders in the body of 

 the sponge. It was only afterwards that it was discovered 

 that these supposed one celled parasites were in reality 

 the egg cells of the sponge itself. This remarkable phe- 

 nomenon is also found in other lower animals for ex- 

 ample in those pretty bell shaped plant animals (me- 

 dusae) ; the eggs of these also remain as naked uncovered 

 cells, which stretch out amoeboid processes, feed them- 

 selves, move, and from which after fertilization the many 

 celled medusae-organism is indirectly or directly devel- 

 oped by repeated division. 



"It is therefore certainly no wild hypothesis but an en- 

 tirely sober conclusion which regards the amoeba as the 

 particular one celled organism which gives us an approx- 

 imate representation of the ancient one-celled ancestral 

 form common to all many celled organisms. The naked 

 simple amoeba possesses a less differentiated and more 

 primary character than most other cells. To this may 

 be added the circumstance that similar amoeboid cells 

 can be shown in the full grown bodies of all many celled 

 animals. For example, they occur as the so called white 

 blood corpuscles among the red blood cells (corpuscles) 

 in human blood and in that of all other vertebrates. They 

 also occur in many invertebrate animals, for instance, in 



