MISCELLANEOUS: EXPERIMENTAL TERATOSIS 625 



the shock produced by excessive loss of water acting on dormant 

 totipotent cells. 



34. I am inclined to think there is nothing in Weissmann's 

 theory making a sharp distinction between somatic and germinal 

 cells. I believe that cells in many young undifferentiated parts 

 are totipotent and that what finally becomes of them, that 

 is whether they avail themselves of their totipotency, or not, 

 depends on circumstances. Under ordinary conditions we know 

 how they behave (that is, physiologically) but under extraordinary 

 conditions they may behave quite differently, that is may at- 

 tempt to reproduce the whole organism. In this begonia, toti- 

 potent cells are distributed in great numbers over its superficial, 

 actively growing parts. They occur, I believe, similarly if not 

 so abundantly in the epidermis of other plants and in the skins 

 of animals, but in most cases require a much stronger shock to 

 set them growing, that is, a tumor, or a parasitic stimulus of 

 some sort. That pluripotent cells should occur in the skin of 

 a man, let us say, seems a very strange thing, yet man has in- 

 herited his skin and all the rest of his anatomy from the lower 

 animals, some of which, for aught we know, may have germinal 

 cells as widely distributed and as sensitive to shock as they are in 

 this curious begonia. No one knows, for instance, what effect 

 a shock of some sort, such as a severe blood-letting or a drastic 

 purgation of the mother, might have on a fetus in the way of 

 starting dermoid cysts or other monstrous growths. The subject 

 is one calculated to provoke thought and lead to further experi- 

 ments. The effects of root-injury on this plant seem to me very 

 suggestive as to the origin of Sereh of sugar-cane, of rosette 

 diseases, of orange wilt, of peach yellows, and of the somewhat 

 similar East Indian spike disease of sandalwood. It has also 

 various other interesting bearings. 



35. That this begonia is more subject to shocks leading to 

 phyllomania than other plants may be conceived to be due to its 

 watery nature and especially to its inheritance of very sensitive 

 and easily permeable cell-membranes. That it is alone in the 

 world, in such behavior, I do not for a moment believe. 



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