242 Shirley Poppies [CH. 



Mendelian method would be to institute breeding experi- 

 ments with individual plants, self-fertilising and crossing 

 these individuals together, and recording the offspring 

 produced by each plant and by each combination. True 

 that by sufficient search flowers can be found which when 

 arranged in order provide a series of intergrades from the 

 darkest red to the whites so nearly complete as to persuade 

 an observer of moderate experience that there is full con- 

 tinuity. Nevertheless, from what we know of every such 

 case to which Mendelian analysis has been extensively 

 applied, there cannot be the smallest doubt that, as in 

 Antirrhinum, the Mouse, and many other examples, the 

 apparent continuity is misleading. It will, when analysis 

 is undertaken, unquestionably be shown that there are 

 definite, pure homozygous types, containing factors which 

 display the usual phenomena of dominance, and segregate 

 in an orderly fashion ; and that though, between these, 

 intermediates may occur, yet they again will be found for 

 the most part to be various consequences of heterozygosis. 

 There may, not improbably, be a residuum of intermediates 

 which cannot be thus represented, but it will be surprising 

 if these are more than insignificant fractions of the whole, 

 owing their peculiarities to various fluctuating influences. 

 The ground will then be approximately mapped, and the 

 laws of colour-inheritance approximately established for the 

 Shirley Poppy. 



The method of Professor Pearson and his assistants 

 dispenses with all analysis. No attempt is made to discover 

 the factors concerned, to distinguish the pure types, or 

 the properties of dominance which they possess. No 

 artificial crosses are undertaken*. The flowers are left 

 uncovered, open to the insects which may introduce the 

 pollen of any other flower which they happen to be carrying. 

 The records show probably with much accuracy the 

 colours of the offspring derived from mothers of recorded 

 colours, and no more. In this attempt to study the laws 

 of heredity of colour, the fathers of the progeny examined 

 are in every case unknown. 



* Self-fertilisation was subsequently tried, but, owing to self-sterility, 

 gave no results. 



