212 Atkinson. 



To show leaf character in more detail a composition consisting 

 of four rosette leaves and three stem leaves was photographed for each 

 parent and hybrid. The smaller rosette leaves in the photograph are 

 younger than the large ones. The stem leaves were selected, one near 

 the base, one about midway, and one a short distance below the inflor- 

 escence, from the main shoot. These are represented in figure 6 with 

 the exception of the stem leaves of tortuosa which were not developed 

 when these photographs were made. The upper row represents nutans 

 (pag. 215) (left) and the three hybrid types (iiutella, pycnella and tortuosa) 

 when nutans is the mother. The lower row^) represents pycnocarpa 

 (left) and the two hybrid types (nutella, pycnella) when pycnocarpa is 

 the mother. 



In the Diagram are tabulated the principal characters which have 

 been studied, in such a way as to show the blending of the contrast 

 characters of the two parents in the Fi hybrida nutella, and also the 

 sorting of characters from the two parents with their recombination 

 into new complexes or mosaics, in the Fj segregates, hybrida pycnella 

 and hybrida tortuosa. In the upper line are arranged the characters 

 of nutans, in the lower line those of pycnocarpa, while in the middle 

 line are arranged those of hybrida tortuosa, hybrida nutella and hybrida 

 pycnella. The lines indicate the source and distribution of characters. 



In Table I are given the explanations of the abbreviations in the 

 Diagram. 



The analysis of the hybrids as seen by an examination of the 

 Diagram shows a distinct linking or association, of certain characters in 

 their transmission to the Fi segregate hybrids, pycnella and tortuosa. 

 The bond between these linked characters is stronger than that of the 

 total composition of either parent, and in the case of certain characters, 

 stronger than the total composition of certain members or organs. This 

 results in a splitting of the total composition of both parents, and also 

 a splitting of the total composition of certain members of the plant body. 

 The splitting, however, occurs almost entirely between characters, not 



^) The photograph of the leaves of nutella in the lower row of figure 6 is a 

 duplicate of that in the upper row for this hybrid. It should have been represented 

 by leaves from the progeny when pydnocarpa was the mother, since there were many 

 plants from which to choose. That it is not so represented is due to an oversight. 

 It was my impression that a photograph of the leaves of nutella on the side of pycno- 

 carpa had been made. In November, 1913, when 1 assembled my photographs I dis- 

 covered that the one representing this rosette was missing, and it was then too late to 

 make one. 



ft 



