No. (i2()] GKrJXTisM IX M( (.rnjXA TABACUM 223 



Maiiiinotli (iiari'owlt'af type) has been crossed with Stew- 

 ai't Cnhan (a li'iant tx pe previously mentioned as oriijina- 

 tin- in (\)nn('<-tirut in CuU-.m ^hade-rown tohacco). and 

 aiM. witli a -\[ainnu)th Wuvlvy tx,:.'. wlii.-h w.-)^ ^.--nred in 

 the F, feneration of the cro^^ Marvhui.l Manniiotli X 

 AVhite Bnrley. In the ero^^ Mar>hin<l Mannncth x Stew- 

 art Cuban, many plants of the Fi generation were grown, 

 all of which were of Manmioth habit of growth. Selec- 

 tions of these Fj plants were grown and bred true to the 

 Mannnotli habit. 



In the cross :\[aryland Mannnotli 9 X l:>urley ^Mani- 

 moth many F, i)lants were grown at Arlington. A'a.. in 

 1018. Of a total of 558 individuals, all were of Mannnoth 

 habit and of this number twenty-otie were yellowish 

 green like the normal White P.urlev varletv, and -J:;: wciv 

 full green in color like tlie Maryland Mannnotli parenl. 



In a study of the reai)])earanee of Mammoth lype^ in 

 the Fo generation of crosses involvinu' Mannnotli and nm-- 

 mal forms, several different coml)inations have been 

 made. In one grou|) botli parents were of l>urley type. 

 In the second group one of the parents was normal ui'een 

 and the other of r>nrley typ(^ In the third uronp both 



In the lii-t -roup. iiiv.)lvino- P.ui'lev roh.i' in both pa- 

 rents, one ot' the parents w:i< the r>nrlev Mammoth >e- 

 <'uiv<l in the F o.'iier.'iti.m of tnr rro^^ Mar\!aiid Mam- 

 moth . White linrh^v. Fr.uii the ero- Mannnotli 

 P>urley i \ m-dinar\ White Ibirlex -\ (iiN F_, plant- weiv 

 grown, of which ]7)S were Mammoth. 'rhi> a \-er\- i-lo-e 

 approxinuition to the theoretical Meiidelian ratio i'>;!> 4 



