CONTENTS. 



Page. 



Introduction ' 



The great variability of tobacco plants 9 



The introiliution and accliinatizatinn i>f varieties 12 



The structure and arrangement of Howers 17 



The necessity for inljreeding 22 



The improvement of the shape of leaves 26 



The modification of the size of leaves 29 



The control of the number of leaves on individual plants 33 



The production of nonsuckering types 35 



The production of early varieties 37 



The improvement of the burning quality 39 



The selection of seed plants 't'^ 



Records of breeding work made in the field -t" 



Permanent records of breeding work 52 



Methods of saving seed 54 



Seed separation 57 



Disease resistance 60 



A new variety produced by seed selection: 



Uncle Sam Sumatra 62 



New varieties produced by hybridization and seed selection : 



The Cooley hybrid 64 



The Brewer hyl^rid 66 



Description of plates 70 



ILLUSTRATIONS 



PLATES. 



Plate I. Fig. 1.— Connecticut Cuban tobacco plants raised in 1903 from unse- 

 lected freshly imported seed, showing generally undesirable types. 

 Fig. 2. — Crop of Connecticut Cuban tobacco plants raised in 1905 

 from seed saved from best plants selected from the field shown in 



figure 1 , showing uniformly a desirable type 72 



II. Fig. 1. — Type of Connecticut Cuban tobacco plants saved for seed 

 production. Fig. 2. — The progeny of a single parent plant of 

 Connecticut Cuban tobacco raised from seed saved under bag 72 



III. Two types of Connecticut Cuban tobacco which have been inbred 



for three years, showing the value of the practise of inbreeding in 

 tobacco 72 



IV. Two rows of Connecticut Sumatra tobacco showing variation in type. 



Row on right, Greenleaf type; row on left, Sumatra type 72 



5 



96 



