Haskell, G.
Following on Mather and Wigan's method of selecting inbred lines of Drosophila for increased hair number which resulted in intra-chromosomal re-arrangements leading to correlated responses. I am now applying this technique using the biometric character cotyledon number to select within the varieties of British inbred tomatoes. These varieties are mostly highly constant and are probably gene eroded. Hence it is difficult to make changes in the tomato population without dealing with very large numbers and having to make F1, crosses between varieties. The method of pleiocotyly I have already used successfully in out-breeding species, such as Brassicas (Haskell, Phytomorphology 4:140-152) and hence it will be of great interest to see what genetic breakdown can be obtained within an inbred commercial variety without it having been previously outcrossed.