Modern Thoughts on the Origin^ Evolu- 

 tion^ and Significance of Life* 



Ihr Alle f iihlt gehelmes Wirken 

 Der ewig -waltenden Natur, 

 Und aus den untersten Bezirken 

 Schmiegt sich herauf lebend'ge Spur. 



—Faust II., Theil. 

 All the secret working feel 

 Of Nature's ever-guiding will, 

 And from the abyss deep and dark 

 Floats gleaming up a living spark. 



RECENT VIEWS ON PROTOPLASM AND 

 ORIGIN OF LIFE. 



By the dissection of living plants and the exposure of their 

 interior structure under the microscope by a moderate enlarge- 

 ment a chambered, or so-called cellular, structure is visible. 

 These chambers appear to be filled with a transparent, aqueous 

 fluid, ascending from the root, and carrying along with it un- 

 assimilated nutritive elements. It is called cell sap. Grains 

 of chlorophyll are frequently floating in it. This element of 

 the plant body had been observed and described before 1840. 



A close observation, however, of any living cell will reveal 

 another substance, mostly in the form of a slimy, viscid, or 

 subsolid mass, either filling the whole cavity, or only clothing 

 the inner wall with a thin layer, or traversing in thin strings 

 the cavity of the cell. The distinct character of this substance 

 was first announced by Hugo Mohl in 1846, and called by him 

 protoplasm. 



This is, in its general bearing, a v^ery well-known, but in its 

 innermost nature a yet totally unexplained, substance. We 

 know about it to a certainty, that it is the basis of life, not 

 alone of plants, but likewise of animals. The protoplasma of 

 each cell also contains a formative differentiation, the nucleus. 



From a chemical standpoint it is composed of not less than 



