1923] Bau: Morphological Characters in Crepis Capillaris 227 



constructed for family 21.140, shows that the correlation between the 

 two is very low. For purposes of calculation, length of lobe is ex- 

 pressed in round numbers of centimeters, the fraction being treated 

 as one when more than half and ignored when less than that amount. 

 The absence of influence of length of leaf on number of lobes is 

 also illustrated by a comparison of the leaf outlines which show practi- 

 cally the same number of lobes on leaves of different lengths and in 

 other cases different numbers of lobes on leaves of practically the same 

 length. From an extended study of the data as well as from observa- 

 tions in the field and green house on various races of Crepis capillaris, 

 I am led to conclude that number of lobes is a definitely heritable 

 character and is not influenced by length of leaf, by soil or by any 

 other environmental conditions under which the plant is grown. 



INHERITANCE OF SIZE OF CAPITULUM 



Goodspeed and Clausen (1915) have determined a number of fac- 

 tors which influence flower size in Nicotiafia. Under the heading, 

 "age of plant," they have considered the difference in size of flowers 

 borne early in the season as compared with those borne late in the 

 season on the same plants as well as the difference in size of flowers 

 during the first blooming season of the plant compared with that of 

 flowers produced the next year and on the same plants cut back and 

 sprouting from the roots. Under the heading "age of flower," they 

 include, first, a consideration of the difference in the size of flowers 

 borne on the terminal inflorescences first coming out of the stem and 

 those borne at the same time on laterals and seconds, and (2), the 

 influence of age on the individual flower by comparing measurements 

 of flowers fully opened before and after shedding pollen. Other factors 

 such as influence of removal of flowers and developing seed capsules, 

 the behavior of cuttings under various conditions, and the influence of 

 soil fertility were also studied. They find that the flowers produced 

 later in the season have usually been of smaller size. By removing all 

 flowers as fast as they are produced, they find it possible to keep 

 the flower size nearly equal to that of the first flowers produced and 

 were able in some cases to double the length of a plant's life. During 

 the period which elapses from the time a flower is fully opened to the 

 time when pollen is shed, there is a considerable increase in corolla 

 spread, and associated with it, little or no increase in corolla 



