PROTOPLASM OR LIVING MATTER. 



IN the preceding study it was found that the cells were 

 of various sizes, shapes, and uses. In some were found 

 such storage stuffs as starch, fats, and mineral substances, 

 in others, and indeed most, might have been noted a more 

 or less homogeneous or granular substance which has come 

 to be known as protoplasm, a substance which Professor 

 Huxley aptly called "the physical basis of life," since life is 

 only known to us in association with this physical material. 

 While a great deal of investigation has been devoted to the 

 study of protoplasm, its chemical nature and its physical 

 structure, and while much has been learned along these lines, 

 still that which is as yet unknown is much greater. An 

 elementary course w r ould not be the place to undertake a 

 study of these properties of protoplasm, yet it is not beyond 

 the scope of even such a course to endeavor to observe some 

 of its more obvious characteristics, and some of the things 

 which it does. It will be interesting to study something of 

 its actual activities, its movements, its behavior under 

 varying conditions of cold or warmth, and to note perhaps 

 certain aspects of its structure. Since such study can only 

 be made with the high power of the microscope it will be 

 necessary to select living things whose structure is such as 

 to render them favorable for observation, i. e., those which 

 are sufficiently transparent to enable one to see through 

 them and note all that takes place within. Certain plant 

 cells are especially favorable subjects, as are also some of 

 the transparent animal organisms, like the common amoeba. 



