44 The MicHoscoPii;. 



leaving those cells containing chiefly enchylema for the elabof-* 

 ation of food. What insight he thus gains into the physiology 

 of living organisms ! 



But he has not yet seen all, for if he is very attentive he soon 

 notices the little grains in the enchylema ; how they promenade 

 along the threads of the reticulum with an activity which varies 

 every moment. Mysterious phenomenon ! Who will explain 

 it ? Why ? A very torrent of questions presents itself, all serv- 

 ing as a stimulus to the imagination. Now if the Nodiluca is 

 irritated by gently tapping with a needle on the cover glass or by 

 sending a slight current of electricity through the water, it will 

 be seen that the protoplasmic reticulum breaks loose from the 

 cell-wall and contracts toward the centre, at the same time 

 dragging with it the granules of the enchylema and expelling 

 the water from the plastic vacuoles. At last the observer may 

 wish to find out the chemical nature and composition of the 

 various parts of this, curious Infusorium. He treats hi.-; Nodiluca 

 to a minute dose of osmic acid and finds that the larger granules 

 of the enchylema are stained black like ebony, an indication 

 that they are of a fatty nature. Next he introduces under the 

 cover-glass a drop of methyl green which at once siezes upon 

 the fragmental portions of the nucleus producing a beautiful 

 green color, and convincing him that they are nuclein. Other 

 arrangements are used to find that the reticulum is formed of a 

 substance called plastin, and the membrane of another called 

 elastin. 



Now if the observer will filter some sea water so as to obtain 

 a quantity of Nodiluca, he can subject them to macro-chemistrV 

 and discover the presence of some soluble ferments as diastin 

 and pepsin. Let this much be«said to show what is meant by 

 the modern science of biochemistry. 



We thus see what is understood by a complete biological 

 study of a living body. It is unnecessary for me to say that 

 this study may be applied to every living being, to every group, 

 and finally to all living organisms, and that thus we would have 

 the study of general biology. 



But from what has been said, this study may also be applied 

 to every cell either as a complete living being or as a simple ele- 

 mentary individuality of organized beings. In this way we 

 have the science of general Cytology^ 



