428 



Dr. W. Kuhne. On the 



and synthetic processes for the accumulation of potential energy in 

 the form of its own consumable substance and the expired oxygen. 



With whatever unassailable correctness this conception comprehends 

 life as a whole, affording a pleasing solution of its antithesis by 

 referring animal activities to nourishment by the plant, the latter to 

 the products of the combustion of the animal body, and both in the 

 last instance to the forces of the sun as original source of all life, yet 

 this did but cast up the sum total of the processes of life, and did but 

 express more intimately than before that which divides the most 

 highly developed branches of the animal and vegetable kingdom, in 

 which the divergence of forms and arrangements is greatest. For 

 by the side of this distinction there exists even between man and the 

 most highly elaborated plant a connexion of a kind quite other than 

 the symbiotic interdependence through the medium of light, air, and 

 food, a community, however, which is not disclosed until we go back 

 to the ultimate elements of organisation. 



As in the animal synthetic processes are not wanting, without 

 which it could not even produce a molecule of the colouring matter 

 of its blood, so in the plant we are acquainted with dissociations and 

 combustion, and also with evolution of heat and movement of masses ; 

 not that by this I refer to those coarser movements which are refer- 

 able to turgescence, but primitive movements, which we find first in 

 the smallest elementary organisms, of which all living beings are 

 made up. 



We have almost in our own persons lived to see the old anticipation 

 of a single kingdom of living things become gradually an established 

 truth through the discovery of the cell. After the ground-lines of the 

 construction of plants and animals out of originally similar nucleated 

 cells had been established by Th. Schwann, and since Darwin's 

 immortal work enabled us to derive everything that ever lived or 

 will live from one single cell, we have come to realise that every 

 single organism renews in itself the work of past ages, and again 

 builds itself up from a germ similar to that from which its most 

 ancient ancestors started. 



This conviction has become so firmly implanted in our generation 

 that now we scarcely feel the gaps which still exist in our actual 

 knowledge, and almost unjustly underestimate that which the inves- 

 tigations of our contemporaries yet add to the cell-theory, as if it 

 were mere work of repetition. And yet it has been very extensive 

 and decisive — for example, the recent researches upon the intimate 

 structure of the cell nucleus — since nothing less results from it than 

 that the reproduction of the cell by fission takes place identically, 

 down to the most minute details, in all animals and plants (1).* 



Now if the shaping of the cell and all the fashioning of forms is an 

 * These numerals refer to the reference notes at end. 



