W. Batkson and Caroline Pellkw 33 



It may be nK'ntimicd tJial. the genetic behaviour of llie diilinary 

 factors introduced in crosses with rogues is normal. For example the 

 rogue Ft from D. A. x E.G. bears the usual yellow and green seeds. 

 One of our D. A. strains throws albino seedlings which die. Such 

 albinos appear as normal rccessives among the offspring of F^ rogues 

 raised from crosses with that strain, and other similar instances have 

 occurred. Clearly therefore there is no general exclusion of the con- 

 tribution of the type-parent, and it is only the features special to the 

 type which are excluded. 



The nature of the difference between Type and Rogue. 



The genetic behaviour is, as we have .said, without parallel, and 

 even for the differences themselves there is no very plain analogy. The 

 most obvious is that distinguishing giant forms from those of ordinary 

 size in several plants, especially in Pn' inula. Provisional counts of 

 the chromosomes in the peas have not shown mnnerical differences, but 

 our experience of such work is small and pending an expert report 

 which we are obtaining, the matter must be regarded as doubtful. In 

 Primula sinensis however Gregory has described a giant race differing 

 greatly in size from the ordinary type though the chromosomes were 

 not more numerous. But in no case, so far as we know, in which giant 

 forms have been observed, do these throw offspring in any way com- 

 parable with our rogues. Nothing of the kind is recorded for Primula 

 kewensis, Oenothera ()i<jas, or either of the giant forms of Primula 

 sinensis. In genetic behaviour all these cases differ entirely from ours. 



In this connexion perhaps the case of tulip " thieves " may be 

 nienti<ined. These plants arise from ordinary, broad-petallcd tulips, 

 and are distinguished by their narrow, pointed petals'. As to their 

 genetic properties we have no information, but the differences between 

 them and the type fi-om which they come is somewhat suggestive of 

 those with which we have dealt. 



Messrs Sutton have called our attention to somewhat similar rogues 

 with e7-ect pods thrown by Broad Beans (FiciM/afta) with drooping pods. 

 We have begun to investigate this case, but we incline to suspect that 

 these rogues are in reality derived from crosses with the variety known 

 as the Horse Bean, in which the pods are erect. 



' SolmsLaubacb, Wei:en uiul Tidpe, Leipzig, 1S90, p. "1 ; ami Krelage, Gard. Chrnii., 

 1881, 11. p. 1K2. 



Jouru. of Gen. v 3 



