Mendel's law of heredity and horticulture. 



37 



B representing blue sap-colour in the flower. 



D representing intensiticatiou of sap-colour in the flower. 



L representing redaction of sap-colour in the wings of the flower. 



The presence and absence of these eight factors in various com- 

 binations and in their varied relations and interactions have given rise 

 to numerous types and colour forms, most of which are familiar in 

 gardens. 



The following table will illustrate this so far as the eight factors are 

 concerned.'^ Other garden forms not found in the table are no doubt 

 due to the presence of other unit factors not yet isolated. 



Factoeial Table for Habit and Flower Colour in the 

 Sweet Pea {Latliyrus odoratus). 



TPWCRBDL Tall, purple standard with blue wings (e.g. wild 

 form, Piiryle hivincible). 



Tall, purple standard with purple wings (e.g. Black 

 Knight). 



Tall, white tinged wuth purple (e.g. Lottie Echford). 

 Tall, red standard with blush wings (e.g. Pcmited 

 Lady). 



Tall, pure white (e.g. Dorothy Eckford). 



Tall, purple cream standard with blue cream wings. 

 Bush, purple standard with blue wings. 

 Oupid, purple standard with blue wings (e.g. 

 Captain of the Blues Cupid). 



Tall, white tinged with purple (e.g. Lottie Eckford). 

 Tall, red standard with red wings (e.g. King 

 Edward). 



Tall, white tinged with red (e.g. Lovely). 

 Tall, pure white (e.g. Dorothy Eckford). 



TPWCRBD 



TPWCRBL 

 TPWCRDL 



TPWCBDL 



TPWRBDL 



TPCRBDL 



TWCRBDL 



PWCRBDL 



TPWCRB 

 TPWCRD 



TPWCRL 

 TPWCBD 

 TPWCBL 

 TPWCDL 

 TPWRBD 

 TPWRBL 

 TPWRDL 

 TPWBDL 



* The remaining factors represent (1) dark leaf axil, (2) erect standard, 

 (3) long pollen, (4) fertile anthers. The precise relationships between these 

 remaining factors have not yet been fully worked out, but results so far have 

 presented some interesting complications. For instance, a partial gametic coupling 

 has been found (in coloured flowers) between the factors for dark axil and fertile 

 anthers (pure white flowers have usually light axils). A partial gametic coupling 

 also exists between the factors for long pollen and blue colour. Further a 

 gametic repulsion between the factors for erect standard and blue colour has 

 been discovered. There is also apparently a somatic coupling between erect 

 standard and light wings and hooded standard and dark wings. In view of 

 these complications these four factors may be for the present omitted. 



