90 THE EVOLUTION OF LIVING BEINGS. 



planting a single individual of Antirrhinum glutino- 

 sum in an experimentgarden, in which a large number 

 of different types of Antirrhinum are cultivated. 



As Antirrhinum glutinosum is selfsterile, we can 

 observe the result at once in F v 



Now the result, obtained in such a case in Bennebroek, 

 was an enormunsly varied F x which could be explained, 

 either by the fact, that the individual of A. glutino- 

 sum had been crossfertilized by a number of different 

 Antirrhinum-types, the pollen of which had been car- 

 ried by humblebees to the different flowers of the glu- 

 tinosum-individual, or by a single, but highly hetero- 

 zygous, type. 



A priori, the former was the most probable but this 

 single experiment was insufficient to settle what had 

 really happened. 



To settle this point, several individuals of A-glutino- 

 sum were planted out and seeds of one of them collected. 



The result was the same: a multiform F v but 

 this time there were pure glutinosum-forms among 

 this F x , which failed to appear in the first one. 



It was thus proved that A. glutinosum was fertilised 

 at least by two of the different types present in the 

 garden viz by A. glutinosum and by at least one hetero- 

 zygous type of A. majus, much more probably by 

 several types, the pollen of which had been brought to 

 the glutinosum plant by insects. 



This experiment is yet in progress with the overwin- 

 tered F 2 plants which of course will continue to cross 

 with one another and with other types present in the 

 garden, thus giving continuously rise to new types, 



