30 THE SCIENCE OF LIFE. 



c. Wandering movement is a modification of the latter 

 form. A portion of the bioplasm is projected forward, 

 and along this temporary arm, or bridge, the semi-fluid 

 molecules flow along, and accumulate at the farthest 

 end. In this manner the white cells of blood, which are 

 particles of bioplasm, wander out of the vessels, perhaps 

 by means of stomata, or holes, in the sides of the vessels, 

 into those tissues of the body where they are needed, 



FIG. 3. Clot of Frog's Blood, with Migrating White Blood-cells. 



Fig. 3. These motions are wholly unlike any which 

 occur in lifeless material. 



2.) Another essential property of bioplasm is growth. 

 The term growth does not mean accretion or addition 

 of material, nor increase of size. A piece of chalk, or a 

 bank of mud, or any non-living thing, may increase in 

 size by additions to its material. Growth in a living 

 thing is different. It is enlargement by nutrition, and 

 depends on inherent motion. In Chap. I, Sec. 13, it was 

 stated that hair would grow on a corpse, but the term 

 grow was used in a popular, and not scientific, sense. 

 Hair is not a living part of the body. Hair or nails may 

 be cut or destroyed without sensation or impairment of 

 the body. They consist of scales of formed material, 



