1867.] 



Relations of Verbasca. 



147 



discussing the obligations of a hypothesis, he remarks, that " Mr. Darwin, 

 in order to place his views beyond the reach of all possible doubt, ought 

 to be able to demonstrate the possibility of developing from a particular 

 stock, by selective breeding, two forms which should either be unable 

 to cross one with another, or whose cross-bred offspring should be 



infertile with one another," "Now it is admitted on all hands 



that at present so far as experiments have gone, it has not been found 

 possible to produce their complete physiological divergence by selective 



breeding If it should be proved, not only that this has not been 



done, but that it could not be done, I hold that Mr. Darwin's 

 hypothesis would be utterly shattered." Professor Huxley, however, 

 though thus strongly insisting upon the absence of facts showing that 

 any degree of sterility has resulted from the crossing of varieties 

 known to have originated from a common stock, states that he does 

 not know a single fact which would justify the assertion that such 

 sterility could not be produced by proper experiment, expressing his 

 belief that it may and will be produced. 



Considering then the as yet positively equivocal nature of the 

 relations between the phenomena of hybridism and mongrelism, 

 together with its important bearings on the converse theories which 

 now divide the scientific world, I trust the reader will bear with me, 

 while giving a somewhat detailed statement of my own experiments 

 on the above phenomena. I venture to premise that they show pretty 

 clearly the relative claims of the two views now held by naturalists 

 on our acceptance, and illustrate also one or two other points of high 

 interest in theoretical natural science. First, for the union of V. 

 ph.amiceum vars. roseum and album, and V. nigrum. 





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Table 1.— Eesults of Pure and Mixed Unions 

 of Verbascum 'pftozniceum, var. roseum and 

 album; and V. nigrum. 



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1. Verbascum phcenicetim by pollen of V. 



pJiceniceum roseum, 



2. V. phceniceum, roseum by pollen of V. 



plweniceum, 



193 



306 



20 

 20 



483 

 680 



