CHAPTER XII. 

 THE EFFECT OF CROSSING LINNEONS. 



On talking with different scientific friends about the 

 views which have gradually developped in my mind 

 about crossing being the origin of species, I have fre- 

 quently heard the objection — which is pretty gene- 

 rally offered against all theories of evolution — that 

 the effect is inconsiderable, compared with the changes 

 wanted to explain the origin of such different groups, 

 say as fishes, reptils and mammals. 



I will return to this question in the next chapter, U- 

 mitlng myself in the present one, to show what the ef- 

 fect of an actually executed cross between individuals 

 belonging to different Liimeons has been. 



It is impossible to treat here of all the numerous 

 forms which result from such a cross; for this I must 

 refer the reader to a book by the author, on the 

 hybrids between different Linneons of Antirrhinum 

 which would have appeared long ago, if the war had not 

 inferfered with the making of the plates. 



But as all that is necessary here, is to show the great 

 diversity which can be the result of a cross, I can suffice 

 by restating, what I said at the IVe Conference de 

 G^n^tique in Paris in 1911 and by reproducing some 

 photographs as illustration. 



In 1910 Professor Baur of Berlin succeeded in cros- 

 sing certain species of Antirrhinum, the hybrids of 



