XVII 



MYSTERY OF THE CELL 337 



The remarkable thing in all these one-celled creatures 

 is that they so much resemble higher animals without 

 any of their organs. The writer of the article Cell in 

 Chambers's Encyclopaedia says : " The absence of a circulating 

 fluid, of digestive glands, nerves, sense-organs, lungs, kidneys, 

 and the like, does not in any way restrict the vital functions 

 of a unicellular organism. All goes on as usual, only with 

 greater chemical complexity, since all the different processes 

 have but a unit-mass of protoplasm in which they occur. 

 The physiology of independent cells, instead of being very 

 simple, must be very complex, just because structure or 

 differentiation is all but absent." All the one-celled animals 

 and plants go through a series of changes forming the cycle 

 of their life - history. Beginning as a nearly globular 

 quiescent cell, they change in form, put forth growths of 

 various kinds, then become quiescent again and give rise to 

 new cells by subdivision or budding. 



This fundamental fact, that all organic life-forms begin 

 with a cell and are wholly built up either by outgrowths of 

 that one cell or by its continued division into myriads of 

 modified cells of which all the varied organs of living things 

 are exclusively formed, was first established about the year 

 1840, and was declared by the eminent naturalist Louis 

 Agassiz to be " the greatest discovery in the natural 

 sciences in modern times." The cell is now defined as 

 I a nucleated unit-mass of living protoplasm." It is not a 

 mere particle of protoplasm, but is an organised structure. 

 We are again compelled to ask, Organised by what ? 

 Huxley, as we have seen in Chapter XV., tells us that 

 life is the organising power ; Kerner termed it a vital 

 force ; Haeckel, a cell-soul* but unconscious, and he 

 postulated a similar soul in each organic molecule, and 

 even in each atom of matter. But none of these verbal 

 suggestions go to the root of the matter ; none of them 

 suppose more than some " force," and force is a cause of 

 motion in matter, not a cause of organisation. What we 

 must assume in this case is not merely a force, but some 

 agency which can and does so apply, and direct, and guide, 

 and co-ordinate a great variety of forces — mechanical, 

 chemical, and vital — so as to build up that infinitely com- 



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