MYSTERY OF THE CELL 347 



is the agency that sets in motion a whole series of mechanical, 

 chemical, and vital forces, and guides them at every step to 

 their destined end ? Again, I urge, let us consider what we 

 have to explain. The matter of the fertilised egg is the 

 millionfold complex substance called protoplasm. It is 

 also mainly living protoplasm. What power gave it life ? 

 It is also (in its essential part, the nucleus) already highly 

 differentiated — it is organised protoplasm. What power 

 organised it ? It is a liquid or semi-liquid substance with 

 slight cohesion ; it gradually forms a cell, which divides and 

 subdivides, till at a certain point the globular mass or layer 

 of cells bends inward upon itself, forming a hollow sac with 

 outer and inner walls. What power determines the cell-mass 

 to take this or other well-defined shapes ? Then, as cell- 

 division and specialisation go on, the rudiments of muscle 

 and bone are formed with totally distinct properties — the 

 one with immense contractility and tensile strength, the 

 other with great hardness and rigidity. Who or what guides 

 or determines the atoms of the protoplasmic molecules into 

 these new combinations chemically, and new structures 

 mechanically ? — combinations and structures which all the 

 chemists and physicists of the world are powerless to produce 

 even when they have the ready-formed protoplasm given 

 them to start with ? Then as the process goes on in an 

 ever-increasing complexity which baffles the microscope of 

 the observer to follow, never diverging at any one point 

 from the precise mode of change which alone leads on to 

 the completed living organism, we are asked to be satisfied 

 with millions of " gemmules," " fundamental units," " deter- 

 minants," etc., which actually do build up the living body 

 of each organism in a prescribed and unchangeable sequence 

 of events. But this orderly process is quite unintelligible 

 without some directive organising power constantly at work 

 in or upon every chemical atom or physical molecule of the 

 whole structure, as one after another they are brought to 

 their places, and built in, as it were, to the structure of 

 every tissue of every organ as it takes form and substance 

 in the fabric of the living, moving, and, in the case of 

 animals, sensitive creation. 



I will conclude this short sketch of cell-life and its 



