LUTHER BURBANK 



various theories put forward in attempted ex- 

 planation. 



There was, for example, a theory that gained 

 popularity a few centuries ago, to the effect that 

 all the individuals that are to descend (in succes- 

 sive generations) from any given germ-cell exist 

 preformed in that cell. In a figurative sense, 

 this fact might be said to be axiomatic. But the 

 advocates of the theory declared that it was true 

 in a literal sense also. 



Out of this thought-tangle arose the famous 

 quibble as to which first existed the chicken or 

 the egg. 



Of course there was not the slightest scintilla 

 of proof of any such mysterious ingulfing of in- 

 finite numbers of future organisms in the micro- 

 scopic cell. And, equally, of course, the theory 

 did not long persist. 



MECHANISM OF THE GEKM-CELL 



Nevertheless, it is interesting to attempt to 

 visualize conditions, even when the conditions 

 themselves lie beyond the limit of microscopic 

 vision. And when the germ-cell is thus visualized, 

 one is forced to conceive of it as made up of in- 

 finitesimal particles of matter that in some way 

 carry preformed the future organism that may 

 grow from it. No one nowadays, however, sup- 

 poses that this aggregation of infinitesimal par- 

 ticles in the germ-cell represents a replica of an 

 adult organism. The conception is merely that 



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