Principles of Heredity 179 



Here Professor Weldon's quotation ceases. It is un- 

 fortunate he did not read on into the very next sentence 

 with which the paragraph concludes : 



" These sports appear to become 



fixed and permanent in the next and succeeding generations ; 

 and the tendency to revert and sport thenceforth seems to 

 become checked if not absolutely stopped*." 



Now if Professor Weldon instead of leaving off on the 

 word "ancestry" had noticed this passage, I think his article 

 would never have been written. 



Laxton proceeds :- 



" The experiments also tend to show that the height of the 

 plant is singularly influenced by crossing ; a cross between two 

 dwarf peas, commonly producing some dwarf and some tall 

 [? in the second generation]; but on the other hand, a cross 

 between two tall peas does not exhibit a tendency to diminution 

 in height. 



" No perceptible difference appears to result from reversing 

 the parents; the influence of the pollen of each parent at the 

 climax or fourth generation producing similar results t." 



The significance of this latter testimony I will presently 

 discuss. 



Professor Weldon next appeals to a later paper of 

 Laxton's published in 1890. From it he quotes this passage : 



" By means, however, of cross-fertilisation alone, and unless it 

 be followed by careful and continuous selection, the labours of 

 the cross-breeder, instead of benefiting the gardener, may lead 

 to utter confusion," 



* The combinations being exhausted. Perhaps Professor Weldon 

 thought his authority was here lapsing into palpable nonsense ! 



f Laxton constantly refers to this conception of the "climax" of 

 as we now perceive analytical variation and recombination. Many 

 citations could be given respecting his views on this "climax" (cp. 

 p. 167). 



122 



