A MANUAL OF 



NORMAL HISTOLOGY 



AND 



ORGANOGRAPHY. 



INTRODUCTION. 

 PROTOPLASM. 



IN all this material world, with its complexity 

 of products, there are but two forms of material 

 things namely, living matter or protoplasm and 

 lifeless or dead matter. Protoplasm is not life. We 

 do not know what life is, but whatever it is, we 

 know it is not a material substance. We cannot 

 see, feel, taste, touch, or weigh life, but we can do 

 all these things with protoplasm. Spencer defines 

 life as the "continuous adjustment of internal rela- 

 tions to external relations" an acceptable concept. 



Protoplasm always reflects life, and it is therefore 

 regarded as the physical basis of life. Protoplasm, 

 whether in plant or in animal, shows a uniformly 

 related structure and has many identical character- 

 istics. It is a colorless, transparent, jelly-like sub- 

 stance, of an albuminoid nature, resembling the 



