8 THE BODY AT WORK 



Chemically, protoplasm is a mixture of substances, chiefly 

 proteid, in a condition in which it is capable of manifesting 

 the phenomena of life. But whether it be more complex and 

 of heavier molecule than either globulin, nucleo-protein, 

 albumin, fibrin, or any other of the nitrogenous compounds 

 which take its place when it is dead ; or whether it be as simple 

 as either of these, but differ from them all in its instability, 

 in the constant flux of its atoms, which" causes it at one time 

 to incline towards one of them, at another time to another, 

 are questions which cannot at present be answered. 



The uncertainty as to the chemical nature of protoplasm 

 is responsible for an unfortunate irregularity in the use of t'he 

 term. It is ex hypothesi the most active, the most living 

 part of an animal cell. If the cell has a nucleus and an 

 envelope, the protoplasm must lie in the space between the 

 two. This part of the cell is therefore often termed, without 

 qualification, the " cell-protoplasm." Frequently the abuse 

 of the word is carried still further. Young cells, leucocytes, 

 nerve- cells, etc., which have no envelope, consist of a nucleus 

 embedded in soft cell-substance. The latter is termed its 

 protoplasm. The cell is described as consisting of nucleus 

 and protoplasm, the term assuming an anatomical significa- 

 tion. Not only is such a use of the term bad, because it 

 indicates a confusion of thought, but it brings with it a train 

 of ambiguities. What are the limits of the protoplasm ? If 

 the cell-body be firmer towards its exterior than it is within, is 

 the denser substance protoplasm, or is it not ? It has not the 

 qualities which are attributed to protoplasm in so marked a 

 degree as has the substance which it surrounds. Hence a 

 distinction is made. The one is " ectoplasm," the other 

 " endoplasm." Within the cell-body are many collections, 

 often in the form of granules, of substances which have not 

 the protoplasmic attributes. They constitute the " deutero- 

 plasm " of certain cytologists. But these enclosed substances 

 may be as far removed from protoplasm as starch grains. It 

 is absurd to use the termination " plasm " for such well- 

 defined products of cell activity as these. The subject is, un- 

 fortunately, obscured by conflicting terms. Nomenclatures 

 which were invented with the object of giving definiteness to 

 our ideas have served but to perplex them. The term " proto- 



