72 CELL INTELLIGENCE THE CAUSE OF EVOLUTION 



intelligence. The following is a description of the pro- 

 tozoa by Ernest Haeckel : 



"Many of the aquatic protozoa have the power of auto- 

 nomous and independent locomotion and this often has 

 the appearance of being voluntary. Among the simplest 

 fresh water protozoa are the (arcellina) little rhizopods 

 that are distinguished from the naked amoeba by the 

 possession of a firm envelope. They usually creep about 

 in the slime at the bottom but in certain circumstances 

 rise to the surface of the water. As Wilhelm Englemann 

 has shown, they accomplish this hydrostatic movement 

 by means of a small vesicle of carbonic acid, which ex- 

 pands their unicellular body like an air balloon ; the spe- 

 cific weight of the cell body which is of itself heavier than 

 water is sufficiently lowered by this. The same method 

 is followed by the pretty radiolaria which live floating (as 

 plankton) at various depths of the sea. Their unicellular 

 body is divided by a membrane into a firm inner central 

 capsule and a soft outer gelatine covering. The latter 

 known as the calymma is traversed by a number of 

 water-vesicles or vacuoles. As a result of an osmotic 

 process carbonic acid may be secreted or pure water 

 (without the salt of the sea water) be imbibed in these 

 vacuoles ; by this means the specific gravity of the cell is 

 lessened and it rises to the surface. When it desires to 

 make itself heavier and sink, the vacuoles discharge, their 

 lighter contents. These hydrostatic movements of the 

 radiolaria attain by simple means the same end that is 

 accomplished in the siphonophora and fishes by air filled 

 and voluntarily contractile swimming bladders." 



You will notice from this description by Mr. Haeckel, 

 that this particular kind of cell understands all the laws 

 of hydrostatics. He understands how to make and in- 

 flate his coat with a gas which lifts him to the surface of 



