W. Bateson and ('ARorjxK Pkm.kw 25 



inasmuch as they threw a Iiighcr pri)p(ntion of aberrants, and it is 

 noticeable that these three plants (122, 137, 145) had on their somatic 

 structure been reckoned as class 3. 



Most of class 3, the real intermediates, must be genetically quite 

 different from the types of elasscis 1 or 2, for instead of throwing a large 

 majority of tj-pes, they give a large majority of rogues. 



From what has been said it will be observed that plants with curved 

 pnds can throw some plants with straight pods, but plants with I'ogue 

 foliage cannot throw offspring with typical foliage. 



As regards thi' correctness of our discriminations of the classes when 

 tested by genetic results, it will be ob-served that in addition to the 

 plant referred to class 2 which behaved like class 3, there were also the 

 three plants assigned to class 3 wiiich behaved like low members of 

 Group A. Judgments therefore based on somatic appearances give in 

 this case a rough, but by no means accurate, indication of genetic 

 behaviour. 



Allowing however for some error in the classification of the families, 

 the proportions in which the aberrant forms are produced by the types 

 are siich as to make it extremely unlikely that they are expressions of 

 any ordinary factorial system. It might for example be sujaposed that 

 the type leaves or the straight pods were each dependent on the 

 presence of one or more factors. Any scheme based on the hypothesis 

 that these factors are distributed in any of the ordinary ways must 

 however fail, not merely on account of the rarity of the aberrant 

 individuals of the various classes collectively, but on account of the 

 numerical relations of the abeiTant classes to each other. On 

 the other hand an equally unconformable phenomenon appears in the 

 circum-stance that the plants of class 3 are able to produce thoroughly 

 typical offspring which breed as true as the types. We have then 

 to reckon with the paradox that the types, without crossing, can 

 occasionally produce the intermediates, and that these, in their turn, 

 can, also by self-pollination, produce types. 



From the fact that the rogues never threw any of the higher classes 

 we at first were inclined to regard them as rccessives and class 3 plants 

 as heterozygotes, leaving the question of the number of factors involved 

 in abeyance. Since class 3 never breeds true and throws both types 

 and rogues, each of which behaves genetically like the other members of 

 those classes, the suggestion that class 3 is heterozygous seems at first 

 sight plausible ; but here again the numerical composition of these 

 families makes any such supposition quite inapplicable 



