COOPERATIVE INVESTIGATIONS ON PLANTS. 



I. ON INHERITANCE IN THE SHIRLEY PÜPPY*. 



CONTENTS. 



Vage 



(1) Material 56 



(2) Coniplexity nf Ileredity in Plants ... 59 



(3) Influence of Knviioniiient on Croi) Constants 62 



(4) Relative Fertility of Different Capsules 66 



(5) Homotyposis 67 



(6) Methods of Measiiring Plant Characters for Inheritance 68 



(7) Re.sults for Parental Inheritauce 71 



(8) Heredit;iry Influence of tbe Uapsule and tlic Plant 73 



(9) Grandparental Inheritance 75 



(10) Colour Inheritance . . ■ 76 



(11) Fratemal Con-elation 77 



(12) Conclusions 82 



Appendix of Statistical Tables 84 



(1) Material. In 1899 at Hampden Farm House on the Chilterus we had at 

 oiir disposal for tho study of homotyposis a considerable strip of gardcn covered 

 with Shirley poppies. The.se were e.xtremely fine phiiits, individuals at the eiid 

 of the season having ofteii liO to 80 and occasionally (iO to SO fruits. An 

 iiivt'Stigalion of the stiginatic bands of these capsules showed niarked inili\ iduality 

 in plants gmwn undcr ap])arently very like conditions of soil, air, rain aiid 

 individual crowding. üf course plants on the horders of the plot had rather more 

 opportuiiity for side development and put forth — on the whole late in the season — 

 poor Howers on low shoots. The capsules of these low flowers had rarely any 

 quantity of fertile seed and often nonc at all. The differentiation of high and low 

 flowers in size of capsuie was not aceonipanied by au equally niarked differentiation 

 in the nuniber of stigmatic bands. Owing to this and the relative fewness of 

 outlying individuals the whole plot was dealt with as producing a fairly homo- 

 geneous mass of plants growing under like conditions. For a tiret approximation 

 capsuie differentiation was ncglected. This rule has bcen adopted in later crops; 



* Draftc'd by K. l'earaou. 



