LIVING MATTER 



57 



■ \*- . •: •:•■ I*- ■ ••,■ 



Fig. 27. Protoplasm 

 moves 



The arrows indicate the 



streaming of the protoplasm 



within the cells 



was suggested by the 

 microscope to the cells 



44. The body and protoplasm. Most 

 of the plants and animals that we know 

 do not look a bit slimy. The proto- 

 plasm does not appear on the surface 

 of most organisms. Even when you 

 cut your linger or pluck a flower you do 

 not expose protoplasm so that you can 

 see it. Indeed, protoplasm very rarely 

 occurs in masses large enough to be 

 seen by the unaided eye. Yet in the 

 course of its growth it builds up the 

 enormous bulk of the elephant or of 

 the massive "big trees" of California. 



45. Cells. From the latter part of 

 the seventeenth century, when the mi- 

 croscope was first able to show such 

 small structures, we have known that 

 the body of every plant and every ani- 

 mal is made up of a number of tiny 

 compartments called cells. This name 



resemblance of a mass seen under the 

 , or chambers, of a honeycomb. During 











Fig. 28. Diagram of a cell 



The mass of the cell content consists of the protoplasmic network, with the coarser- 

 grained nucleus. Within the protoplasm are more solid bodies, and droplets of more 



liquid substances 



the past hundred years it has been found that the living con- 

 tents of a cell is protoplasm. When we look at an organism 



