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JOUBNAL OF THK KO^ AL HORTICULTURAL SOOTETY 



SWEET PEA ' AUDREY CRIER/ 

 AN EXPLANATION OF ITS VARIABILITY. 

 By T. H. Dipnall, F.R.H.S. 



Several of the most beautiful Sweet Peas seem to be quite unfixable, 

 notably Audrey Crier, Miriam Beaver, Olive Ruffell, and Syeira Lee, 

 which is almost, if not quite, identical with Miriam Beaver. 



I have long been interested in this peculiarity, but it was not until 

 last summer that it occurred to me that a satisfactory explanation might 

 be found on Mendelian lines. In a short trial row of Miriam Beaver I had 

 forty-one plants of Miriam Beaver true, twenty of Helen Grosvenor, and 

 eighteen of Romani Rauni, numbers having a ratio so near the 1:2:1 

 that we should expect if Miriam Beaver were a heterozygote, and the other 

 two the dominant and recessive, that any other conclusion seemed im- 

 possible. The number of plants grown, however, was too small to admit 

 of certainty, but it looks as if Miriam Beaver were an intermediate form 

 between Helen Grosvenor and Romani Rauni, and consequently an instance 

 of imperfect dominance. In this case, moreover, I had no means of learn- 

 ing the parentage of Miriam Beaver, and consequently cannot arrive at 

 the truth with certainty. But with Audrey Crier I am fortunately in a 

 better position. This lovely pea seems to be quite unfixable, and always 

 throws the same rogues. There are four varieties which constantly appear : 

 first, Audrey Crier proper, a beautiful salmon-tinted pink ; secondly, a 

 pure white, Etta Dyke ; thirdly, a pale pink on a white ground. Countess 

 of Northbrook ; and fourthly, an orange pink, Helen Lewis. 



Thanks to the courtesy of the raiser, Mr. C.W. Breadmore, to whom 

 I wrote at a very busy time, and who replied almost immediately, evidently 

 knowing that his dat qui cito dat, I have been able to work out what I 

 think is a satisfactory explanation of the vagaries of this pea. I started 

 on wrong lines, but in the course of a correspondence with the Editor, he 

 kindly sent me a copy of the proceedings of the Cambridge Philosophical 

 Society containing an account of valuable work done by Mr. and Mrs. 

 Thoday on " The Yellow Tinge in Sweet Peas (Vol.XVI, Part I. p. 71 sq.), 

 from which I have derived very great assistance. 



Mr. Breadmore tells me that Audrey Crier was raised by crossing 

 Countess Spencer with Dorothy Eckford, and that the Fj generation gave a 

 pea of the grandiflora type, having the colour of Audrey Crier. This colour 

 is important, as we shall see later on. 



Mr. and Mrs. Thoday in the course of their experiments with Dorothy 

 Eckford and Queen Alexandra came to the conclusion that, in addition to 

 the two factors C and R to whose combined presence colour is due, there 

 were three other factors involved in the production of a yellow tint. Two 

 of these are recessive, and one dominant. The dominant factor D gives 

 a magenta tint to the colour introduced by R. 



The second factor y gives a yellowish flush to the sap, which is sup- 

 pressed when the factor (Y) is present. The third factor, called X by 



