180 A Defence of Menders 



Here again the reader would have gained had Professor 

 Weldon, instead of leaving off at the comma, gone on to 

 the end of the paragraph, which proceeds thus :- 



" because, as I have previously stated, 



the Pea under ordinary conditions is much given to sporting 

 and reversion, for when two dissimilar old or fixed varieties 

 have been cross-fertilised, three or four generations at least 

 must, under the most favourable circumstances, elapse before 

 the progeny will become fixed or settled ; and from one such 

 cross I have no doubt that, by sowing every individual Pea 

 produced during the three or four generations, hundreds of 

 different varieties may be obtained ; but as might be expected, 

 I have found that where the two varieties desired to be 

 intercrossed are unfixed, confusion will become confounded*, 

 and the variations continue through many generations, the 

 number at length being utterly incalculable." 



Professor Weldon declares that Laxton's "experience 

 was altogether different from that of Mendel." The reader 

 will bear in mind that when Laxton speaks of fixing a 

 variety he is not thinking particularly of seed-characters, 

 but of all the complex characters, fertility, size, flavour, 

 season of maturity, hardiness, etc., which go to make a 

 serviceable pea. Considered carefully, Laxton's testimony 

 is so closely in accord with Mendelian expectation that 

 I can imagine no chance description in non-Mendelian 

 language more accurately stating the phenomena. 



Here we are told in unmistakable terms the breaking 

 up of the original combination of characters on crossing, 

 their re-arrangement, that at the fourth or fifth generation 

 the possibilities of sporting [sub-division of compound 

 allelomorphs and re-combinations of them ?] are exhausted, 

 that there are then definite forms which if selected are 



* Further subdivision and recombination of hypallelomorphs. 



