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THE AMERICAN NATURALIST [Vol. XLV 



shade and of the tomato were decapitated and reciprocal 

 grafts were made. In making these unions the graft was 

 cut either wedge-shaped or saddle-shaped at the point of 

 junction with the stock. The graft and stock united 

 readily whether the nightshade or tomato was used as the 

 stock. After the union was complete the plant was again 

 decapitated, the cut being made through the region where 

 the union had taken place. The cut surface thus exposed 

 is composed of tissue derived from the two members of 

 the union and from this cut surface a callus soon develops 

 from which numerous adventitious buds quickly arise. 

 It was thought that from some of these adventitious buds 

 arising at the point of the junction of the graft and stock 

 there might be produced shoots which would combine the 

 characteristics of the two, or at least might be composed 

 of tissue derived from the two parents. 



Naturally the great majority of the shoots arising 

 from the cut surface of the stem were either pure night- 

 shade or pure tomato. But finally shoots were observed 

 which were evidently of mixed origin. The first of these 

 graft-hybrids were obviously composed of pure elements 

 derived from the two parents. Some of these shoots 

 were almost equally divided by a median line on one side 

 of which the organs — stem, leaf, etc. — were those of the 

 nightshade, while on the other the organs were evidently 

 derived from the tomato. Sometimes a leaf was nearly 

 equally divided. In most cases one or the other of the 

 parents predominated, but there was no intermediate 

 region between the two kinds of tissues and organs. It 

 is clear that such monstrous forms, for which Winkler 

 proposes the name ' ' chimaera, ' ' are not hybrids in any 

 true sense of the word, but have arisen from buds in 

 which there was a mere mechanical coalescence of tissue 

 from the two parent forms at the junction of the stock 

 and graft. 



Further experiments, however, resulted in the produc- 

 tion of shoots in which the characteristics of the two 

 parents were so intimately combined, that their discov- 



