Mendelism in Great Britain 



87 



in Cambridge by Professor Biffen and 

 his co-workers, and there is no doubt 

 that as time goes on even better and 

 more profitable varieties will be at the 

 service of the British farmer. 



It is pleasant to be able to record that 

 the importance of the work has been 

 recognized by the Government, who 

 have placed a considerable annual sum 

 at the disposal of the School of Agri- 

 culture for research in plant-breeding. 

 This has rendered possible an increase 

 in the scope of the work, and experi- 

 ments are now being carried out on 

 other plants besides cereals. Among 

 investigations now under way are some 

 concerned with the transmission of 

 fertility in fruit-trees, while the strik- 

 ing success of Biffen's work on the 

 nature of immunity to rust in wheats 

 has led to the search for naturally im- 

 mune individuals in other forms of 

 plant-life. Experiments with potatoes 

 have been in progress for several years, 

 and, thanks to the energy of Dr. Sal- 

 aman, working on his own estate near 

 Cambridge, and of Mr. Lesley, of the 

 School of Agriculture, the formation of 

 a decent potato, naturally immune 

 to Phytophthora infestans, seems within 

 measurable distance of realization. 



WORK WITH POULTRY. 



Nor are the researches at Cambridge 

 confined to plants. Poultry was one of 

 the first subjects of experiment by Bate- 

 son, and during the past ten years much 

 has been learned of the transmission of 

 various characters. Offering as they do 

 a number of features showing sex- 

 linked inheritance, poultry are of im- 

 portance for gaining an insight into the 

 nature of sex, and of studying the pe- 

 culiar influence of each sex in the trans- 

 mission of hereditary properties. Sev- 

 eral of these sex-limited characters are 

 now under investigation at Cambridge, 

 while parallel experiments are being 

 carried on by Professor Bateson at 

 Merton. 



Two other series of experiments likely 

 to lead to knowledge of economic 

 value are also being carried on at Cam- 

 bridge. The first of these is concerned 

 with the inheritance of size, and consists 

 in carefully following out the result of 



a cross between an ordinary fowl and a 

 bantam. The work is not yet sufficient- 

 ly advanced to permit of complete 

 analysis, but the nature of the F2 gen- 

 eration raised last year strongly suggests 

 that size depends upon definite factors 

 which exhibit ordinary Mendelian seg- 

 regation. The other set of experiments 

 mentioned concerns the inheritance of 

 the brooding instinct in the hen and of 

 the brown color of the egg-shell. In 

 England brown eggs are of greater value 

 than white, but hitherto no breed laying 

 brown eggs and in which the hens never 

 want to sit has yet been established. 

 It may be that brown eggs are incom- 

 patible with the non-broody habit, just 

 as it is sometimes stated that a breed of 

 cattle cannot be at the same time first 

 rate in both milk-production and beef. 

 It is hoped that the experiments in 

 progress will eventually give definite 

 evidence upon this point. 



Experiments have also been under- 

 taken with sheep where the results of a 

 cross between merino rams (from Aus- 

 tralia) and Shropshire ewes are being 

 carefiilly followed. The experiments 

 have just reached the F2 generation, 

 and it is hoped that the knowledge 

 gained from them will eventually render 

 it possible to combine the fieece of the 

 merino with the good mutton qualities 

 of other breeds. 



sweet-pea EXPERIMENTS. 



Besides the work just mentioned, 

 there are other sets of experiments 

 being carried out at Cambridge and 

 Merton which may be regarded as 

 forming a group by themselves. Bate- 

 son in 1905 was the first to describe in 

 sweet-peas a remarkable case in which 

 two characters each exhibiting ordinary 

 Mendelian segregation nevertheless 

 showed a peculiar distribution with re- 

 gard to one another. In this particular 

 instance the characters dealt with were 

 color, blue being dominant to red, and 

 pollen-shape, long being dominant to 

 round. Blue long x red round gave blue 

 long in Fl, and in F2 the expected ratio 

 3 blue: 1 red and also 3 long: 1 round. 

 But the proportion of rounds among the 

 blues was only about 1 in 12, whereas 

 among the reds the rounds were in 



