DESCRIPTION OF PLATES. 71 



Plate V. The two plants shown in this ilhistration. one hearing few small 

 suckers, and the other many large suckers, represent the average variahility 

 of tobacco plants as regards the sucking habit. The plants are of the 

 same variety, grow side by side in the row, are of the ^anie age. and were 

 grown under similar conditions in every respect. The leaves of the plant 

 bearing lew suckers are uniformly wide and round, while the leaves of the 

 plant liearing large suckers are long and pointed, and have a tendeucy to 

 vary markedly in size from the top to the base of the plant. This char- 

 acter is hereditary and consequently the suckering tendency may be con- 

 trolled by tobacco growers by seed selection. 



Platk VI.. Fig. 1. — The characteristic variability of tobacco plants as regards 

 time of maturity, as shown in this illustration, is a matter of conuuon 

 obscrvatit)n in tobacco Ileitis. The difference in the time of ripening of the 

 leaves in the individual plants is of special importance in the tobacco crop, 

 from the fact that in most cases all of the plants in the field are harvested 

 at one time, and overripe or underrii)e leaves are inferior in quality. For 

 this reason it is desirable that the plants mature uniforndy thruout the 

 field. Fig. 2. — The two rows of tobacco plants shown in this illustration 

 demonstrate the possibility of securing uniform early or late strains of 

 tobacco by seed selection. The two rows were grown under the same 

 conditions. 



Plate VII. The character of the burn of leaves of individual tobacco plants 

 varies in a marked degree, even among plants of the same variety grown 

 under the same conditions and treated alike in the curing and fermenting 

 processes. The two rows of plants in this illustration were grown from the 

 bagged seed of two plants of the same field, growing side by side, one a 

 plant producing good and the other poor burning leaves. These two 

 progeny I'ows inherited uniformly the character of burn of the parent 

 plants, demonstrating that it is possible to improve the quality of burn in 

 a variety of tobacco by seed selection. 



Plate Y II I. —The Connecticut-grown Sumatra tobacco produced a number of 

 types of tobacco very different in all characters. The two rows of plants 

 shown in this illustration are the progeny of two representative plants of 

 these types, grown under the same conditions and showing the striking 

 uniform inheritance of the characters of the parent plants. 



Plate IX. Fig. 1.— The row of tobacco plants in the left in this illustration, 

 raised from heavy seed, shows the more vigorous growth, earlier maturity, 

 and greater uniformity of plants raised from heavy seed, compared with 

 the less vigorous plants raised from light seed shown in the row on the 

 right. Fig. 2.— The row of small plants shows the dwarfing effect of the 

 root-rot in Connecticut Sumatra tobacco, w'hile the row of vigorous plants 

 shows a resistant strain secured by seed selection. 



Plate X.— The two rows of the Cooley Hybrid tobacco shown in this illustra- 

 tion were grown under shade in the Connecticut Valley. The uniformity 

 of plants and the shape, size, and character o fleaves shown in these 

 rows are characteristic of this variety of tobacco. There is no decided 

 breaking up in type following hybridization, as is the case in other plants. 



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