FURTHER EXPERIMENTS ON THE INHERITANCE 

 OF " DOUBLENESS " AND OTHER CHARACTERS 

 IN STOCKS. 



By EDITH R. SAUNDERS, 

 Lecturer and late Fellow of Newnham College, Cambridge. 



TABLE OF CONTENTS. 



PAGE 



Statement of conclusions arrived at in the earlier experiments .... 303 

 Later experiments on the inheritance of " doubleness " and plastid colour . . 306 

 I. Races which were obtained only in the double-throwing form . . . 300 

 II. Races which occur both in the form of double-throwing and non-double- 

 throwing strains .......... 311 



III. Proportion of doubles obtained from the eversporting strains when self- 



fertilised or inter-crossed 317 



IV. Constitution of the zygote and segregation in the eversporting forms . 321 

 V. Segregation in F^ crossbreds derived from two eversporting forms and 



statement of the results obtained in ^2 324 



VI. Constitution of the zygote and segregation in the pure-breeding (non- 

 double-throwing) strains 334 



VII. Segregation in Fy crossbreds derived from unions between eversporting 

 and non-double-throwing forms and statement of the results obtained 



in F2 336 



VIII. Summary 356 



Appendix. Note 1. On the relative viability of seeds giving rise to singles and 



doubles 361 



Note 2. On the inheritance of the branched and the unbranohed 



habit 368 



Note 3. On certain sap-colours not dealt with in the earlier accounts, 



and on the constitution of the sulphur-white race . 369 



Statement of conclusions arrived at in the earlier 

 experiments. 



The experiments recorded in the present paper form a continuation 

 of those of which I have already given some account elsewhere', and it 

 may be well, before considering these later records, to recall the main 

 conclusions given in the earlier accounts. 



' Reports I — IV to the Evolution Committee of the Royal Society. In regard to 

 "doubling" see II, 1905, p. 29; III, 1906, p. 44; IV, 1908, pp. 4, 36. 



