I. Inherltance in Shirle// Popp;/ 67 



the refinoment of separat iiig a siiiall percentage of outlyiiig imlividuals being more 

 apparently thau really advantageous. For, given the same soil and climate, there 

 must, if any considcnible number of ])lant,s be dealt with, bc subtle individual 

 advantages or disadvantages to individual plants in the crop dne to slight 

 dift'erenccs in soil and Situation, to thinning, teuding or insect attack. Siniilar 

 advantagcs or disadvantages, however, occur in the casc of individuals, who are 

 offspring of the same parents in nien, horses or dogs, and do not therefure destroy 

 all possibility of comparative study. 



In 1!)0() F. W. Oliver also grew a crop of Shirley Poppies at Chelsea. 

 These showed a very niarked difference in the mean number of stigmatic bands 

 per capside as well as in the number of capsules per plant. We have then to 

 recognise the factors : (i) considerable individuality as expressed by the homotypic 

 correlation in plants grown under liko onvironment, (ii) considerable difference in 

 mean result for two crops grown in different environments, i.e. with differences of 

 soil, tending, climate, atmosphere, etc. 



The Shirley Poppy seemed excellent matcrial for testing the laws of inheritance 

 in plants, partly because of the healthy strong crops which can be raised under all 

 sorts of conditions with small amount of attention; partly, because of the ease 

 with which the stigmatic bands can be counted. In sorae of the series to be 

 considered below colour has also been recorded, but the difficulties attaching to 

 a satisfactory study of individual flowers have permitted at present only of limited 

 consideration of this point. Further expei-imcnts in this matter are in progress. 



In 1900 K. Pearson collected (i) all the seed from every capsule of 2i* 

 individuals out of his 176 Hampden plants; (ii) the seed from the capsules of 

 a great variety of poppies sorted into groups of capsules having 8 to 18 bands; 

 (iii) a mass of seed from all capsules aud plants without diserimination. We had 

 thus three lots of seed to be known as : (a) Individual Plant Seed: (ß) Individual 

 Band Seed and (7) General Seed. In later years an additional type : (S) Individual 

 Capsule Seed, was dealt with. 



From these lots of seed the following crops were grown in 1900 : 



(A) Highgate Crop. By the courte.sy of the Misses Sharpe this was sown in 

 a piece of meadow broken up for the first time for garden purposes. The soil was 

 very poor and purposely not enriched in any way, the crop had an extremely hard 

 struggle for existence at all, only a small percentage of the seed reaching maturity; 

 the crop needed no thinning and was left to itself There were only two or three 

 capsules per plant, and the sizes of these as well as of the plants themselves were 

 inferior even to F. W. Olivers Chelsea crop of the preceding year. Only seed 

 of type (a) was dealt with, (7) failing entirely. In well tended and watered beds 



* It would doiibtless have been better to start with more thaii 21 individual plants, but besides 

 sclecting plants with a sufficient number ot capsules, we had by the conditions of the homotypic 

 experiments to wait tili the end of the flowering season, and then mauy of the plants had scattered 

 their seed. 



Biometrika ii 8 



