14 THE AMERICAN NATURALIST [Vol. LV 



As regards Campanula carpatica " pelviformis" and 

 Begonia Davisii, experiment has shown that the peculiar 

 kind of segregation which the^^ exhibit may recur in 

 their offspring. In the Begonia, if the female of Davisii 

 be fertilized with pollen of an ordinary double tuberous 

 Begonia, the doubleness so introduced stays on the male 

 side jusi as the doubleness of its own male does, and a 

 plant so bred has its pollen all double. But if the male 

 of Davisii be used on the female of an ordinary single, 

 there is no restriction of doubleness to either sex of the 

 offspring. The peculiarity of Davisii must therefore be 

 attributed to the special properties of its female side. 

 The Campanula case is complex and has not yet been 

 fully explored, but at least from the female side of pelvi- 

 formis plants have been raised which retain the proper- 

 ties of the mother as regards the distribution of the 

 white and blue colors. 



"We have at the John Innes Institution been lately in- 

 vestigating a similar case in flax, which, though compar- 

 able, has some special features. A dwarf flax {Linum 

 usitatissimum) of unknown origin, presumably a stray 

 seedling of one of the varieties grown for oil, was fer- 

 tilized with pollen from our tall tiber strain. Both par- 

 ents breed true to the fully hermaphrodite condition, with 

 anthers perfectly formed, and the Fj plants were normal 

 in this respect. F2 consisted of hermaphrodites, and a 

 recessive form with aborted anthers, generally conta- 

 bescent and not dehiscing at all, but having occasionally 

 a few grains of good pollen. The ratio was a normal 3 : 1. 

 The recessive, having occasional grains of pollen, self- 

 fertilized, gave similar plants with anthers wholly or 

 almost wholly aborted. The normal F2 hermaphrodites 

 gave in F-j families which showed that some of the F2 

 plants were pure normals, others heterozygous in the 

 ordinary way. But when the recessives were fertilized 

 with pollen from three several varieties of tall fiber flax, 

 only recessives were produced. These tall flaxes there- 

 fore are normally heterozygous for the recessive or "sub- 

 female" condition, and this in segregation is perman- 



