GIGANTISM IN NICOTIANA TABACI M AND ITS 

 ALTERNATIVE INHERITANCE 



ALLARD 



Bureau of : 

 roTON, D. C. 



Wi i iiix I'ccciit years observers working with dil¥erent 

 varietii- of Xlcofnuni idhacum g-rown commercially in 

 the ViiittMl States and el-ewliere have recorded tlie sud- 

 den aiiiicaiance of occasional liiaiit plants of abnormally 

 high leaf number. Kxce]>t in height and number of 

 leaves, wliich may be increased several times above the 

 usual nunil)er. the>e giant plants in general appearance 

 do ]iot (h'])art widely from the varietal type from which 

 tliey took tlieir origin. The great increase in number of 

 leaves, together with a greatly elongated main stem, is 

 acconi]^anied by a period of vegetative vigor of such long 

 duiation that blossoming does not normally take place 

 when the ]^lants are growing in the field. In order to ob- 

 tain -eed from >ucli ]»lants, the usual ])racti-e lias been 

 to ii-an-phint the root- and -tub, oi- even the i»lants en- 

 tii'e. to the ureenhouse ill the fail, whei'e veuetative vigor 

 i- ivMuned with the final pro.luction ..f normal l)lossoms 

 and M'ed <luring tlie winter. Plant- of thi- hal)it of 

 growth have Ixm'U recorded in the Sumatia. Maryland. 

 ('ul)au and Connecticut Havana ty})es of tobacco. 



Occurrence of Gigantism in Different Varieties 

 The first published record of gigantism in tobacco ap- 

 pears to have been made in 1905 by Hunger (1905), work- 

 ing witli tol)a<*co in Sutnati-a in connection with an inves- 



(iarner (1!M-J) mentione<l a Maryland Mammoth type, 

 the oriuin (tf which wa- a--oclated with a cro-- between 

 tWM .•nmmon vai-ietie- of Maryland tobac-... 



llaye- and P,einhart iVMA) reported the occurrence of 

 218 , 



