NECESSITY EOR INBREEDING. 23 



tions for curing as were consistent with the practical handling of the 

 crop. The leaves of plants selected for seed were harvested sepa- 

 rately and labeled so that the product of each plant could be intelli- 

 gently used in comparative tests of the cured and fermented crop. 

 This labeling process involved considerable extra work and attention 

 in the field, curing sheds, and warehouses, but was absolutely neces- 

 sary for a definite selection of seed plants for the next season's use, 

 based on the character of the fermented tobacco. 



The rows or plats of plants grown from seed of individual plants 

 saved under bag, i. e., self-fertilized seed, showed remarkable uni- 

 formity in type, size, shape, and appearance of leaves, habit of 

 growth, and all other characters, and conformed closely to the type 

 of the parent plants from which the seed was saved. 



Plate II, figure 1, shows a type of parent plant and Plate II, 

 figure 2, the progeny of this plant, raised from self-fertilized seed. 

 From this illustration it can be seen that the transmitting power of 

 tobacco is most strongly marked and the progeny of plants raised 

 from inbred seed remarkably uniform in all characters, every plant 

 closely resembling the parents. In the hundreds of tests of this char- 

 acter which have been carried on by the writers during the past three 

 seasons, not only in the Connecticut Yalley but in Maryland and 

 Florida, the benefits to be derived from using inbred tobacco seed 

 have been confirmed and emphasized. It is true that some plants 

 have the power of transmitting their characters to their progeny 

 more strongly than others, but on the whole every case under obser- 

 vation has offered additional evidence of the value of the practise of 

 saving tobacco seed under bag, free from possible cross-fertilization. 



The continued saving of self-fertilized seed for three seasons 

 has furnished no evidence of a decrease in the rate of growth or 

 constitutional vigor of tobacco plants as a result of this practise. 

 On the other hand, by reason of the selection of the best plants in 

 the different varieties every season there has been a marked increase 

 in the productiveness arid the general vigor of constitution of the 

 varieties under consideration. This conclusion is emphasized by the 

 vigorous and productive strains of Connecticut tobacco shown in 

 Plate III. 



Self-fertilization is the closest possible degree of inbreeding, and 

 it is the general impression that this practise is usually associated 

 with a loss of vigor of growth, with a predisposition to disease, and 

 other undesirable results. In tobacco, so far as our exjDerience goes, 

 this does not happen, and the exact opposite of "this condition obtains, 

 viz, that inbreeding is beneficial to the general development of the 

 variety. 



It is unfortunate that it is impossible to present tabular data at 



96 



