1 86 Segrerjation of a Quantitative Character in Beans 



With regard to the general conditions under which the further ex- 

 periments were conducted, in 1914, 1915 and 1916 the beans were grown 

 in the voliere in the experimental part of the Botanical Garden. The 

 year 1916 was in every way unfortunate. The weather was bad and the 

 ground " bean- tired." The results for 1916 are therefore not as good as 

 for the other years. For that reason, the beans were sown in 1917 and 

 1918 outside the voliere in the experimental garden. The ground in 

 which the beans were planted was, as far as possible, uniform, and they 

 were planted exactly equidistant from each other. More or less room to 

 grow has considerable influence on the size and number of the beans 

 produced by a plant, and to avoid disturbances from that cause, any gaps 

 occurring from failure to germinate were filled with beans from another 

 pure line with violet pigment in the flowers and stems and black seeds 

 of a different shape. No trace of cross-fertilisation ever appeared in 

 either race, inside or outside the voliere. 



The beans are sown in May and ripen about the end of August, and 

 after harvesting are spread out to dry in a loft. They must not be dried 

 too quickly nor subjected to much warmth or the pods will open and 

 much material be lost. When the beans are thought to be dry, weighing 

 tests are made, a sample fresh from the pods being weighed, left for a 

 few days in a warm room and again weighed. When the weight is con- 

 stant all the beans are removed from the pods, plant by plant, and carefully 

 examined. Any that may be unripe, all misshapen beans and all that 

 are spotted with fungi, though only to the extent of slight discoloration, 

 are rejected. The reasons for the rejection of these first two classes of 

 seed are obvious. Beans that are unripe or misshapen will give measure- 

 ments that are abnormal and incorrect. But neither unripe nor misformed 

 beans are numerous, and misformed ones occur usually together in pods 

 that have been curved in growth by some accident of position or by 

 injury. The most serious ground of rejection lies in the attacks of fungi 

 and seeds so injured must be rejected for two reasons. In the first place, 

 it cannot with certainty be said that the fungus is without influence on 

 the size of the bean, and, in the second place, not only are such beans 

 useless as seed themselves, but they are liable to infect others stored in 

 the same glass. 



Each year the original pure line and the mutant were sown as con- 

 trols, and in 1916, 1917 and 1918, when the number of rows had become 

 big, ten rows of controls were sown in all, five of E and five of M, dis- 

 tributed, one of each together, at equal distances over the field. The 

 variation in the controls will give a picture of the differences due to 

 inequalities in the ground. 



