1 50 AGE, GROWTH, AND DEATH 



the protoplasm of these cells, then split off from them, 

 and come to lie in the intercellular regions, so that 

 here we have another type of cell differentiation 

 brought to our notice, one in which the product is 

 separated from the parent body to which it owes its 

 origin. Now you will perceive immediately, if you 

 'recall the series of pictures which have just passed 



FIG. 56. EMBRYONIC SYNCYTIUM FROM THE UMBILICAL CORD OF MAN ; 

 c, c, cells ; F, fibrils. 



before us, very great differences in the types of differ- 

 entiation which occur in the body, and had we time 

 we might find a very much larger range easily to be 

 represented before us. 



In the second lecture a picture was projected upon 



