186 Davis. 



biennis X muricata = muricafa <ind muricafa X biennis = biennis. Ac- 

 cording to DE Tries the hybrids are notabh- patroclinous in the morphologj- 

 of the rosettes, in the color and morphology" of the foliage, in the character 

 of the branches whether straight [biennis) or nutaut (nniricata) and 

 whether firm (biennis) or weak and susceptible to the Botrytis rot 

 {muricata), in the color of the petals whether a dark yellow (biennis) 

 or a lighter yellow (muricafa), in the pubescence of the cah"s, ovar_v and 

 capsule. De Vbies states that some characters, especially those of 

 flower structure, are present in the hybrids as blends. Ob^•iously the 

 application of the term patroclinous is relative to the degi-ee of resem- 

 blance and a plant with respect to certain characters may be more or 

 less patroclinous according to the judgment of different observers. The 

 attitnde of DE Veies has its chief interest "with reference to the con- 

 ditions reported by him in the double reciprocal, sesquireciprocal and 

 iterative hybrids. These I shall not discuss until I have carried my own 

 crosses into further generations. 



At present in my studies I am impressed not so much by the 

 patroclinous tendencies of the hybrids as by the fact that however far 

 the resemblance of a character to the pollen parent may be manifest the 

 hybrid does not appear to duplicate exactly the structure in question. 

 Thus the two sets of the hybrid rosettes differ strongly from one another 

 but are not exactly Uke either parent. The foliage of the hybrids does 

 not duplicate the foKage of the pollen parents ; there are differences in the 

 size and proportions of the leaves and in the serration of the margins. 

 Branches on the same plant may be both straight and nutant. The 

 color of the foliage is variable over younger and older portions of a 

 plant and the depth of color in the petals is variable in smaller and 

 larger flowei*s on the same plant. The pubescence of the sepals, ovaries 

 and capsules on my hybrids has appeared as a blend. Furthermore, 

 the hybrids are certainly raatroclinous in the length of the bracts rela- 

 tive to the length of the buds thus contradicting in the inflorescence 

 the general patroclinous tendencies throughout the plants. And, as 

 de Tries has noted, the flower structure presents blended relations of 

 its parts in varying degrees. Thus to me the conclusion of greatest 

 importance is the recognition of the influence of both parents in the 

 hybrids even in structures where the patroclinous and matroclinous 

 conditions are most conspicuous. 



Two investigatore have taken the patroclinous tendencies of the 

 hybrids of biennis and muricafa to mean that the charactei-s concerned 

 are absolutely identical with the same characters of the pollen parent. 



