A. I.. ii\(,i':ii(Mii;\. factkhis (ikm^tioi i:s. 



GENETIC FACTORS AND NON GENETIC FACTORS IN THE AMELIORATION 

 AND BREEDING OF NEW VARIETIES 



Two kinds ol' l'aciors (•(inpri'alo in Lin- (level()|)nirnl ni' llic urgaiiisiiis : Ihc 

 s^iMiolic factors and llic nnn-gcnolir raclors, Ihe environnienl in llir widesl 

 scnso. Thosp cullivaled spocies wliich hâve Uip widosi dislrilmlimi aie liiosc 

 wliicli liave llie grcatcsl g(Mielic varialiililv, Uioso, in wliirh a Si'rcil niiinlM'i- dT 

 f>-enplic faclors an» preseni in, sonie absent IVom olhoi- individiials. 



The study and llie manipulaiion of (ho genelic l'arlors is llie work of Ihe 

 l)iologi.sl; tlie slndy ûf Iho non-genolio faclors and also tlio ohoice belwecn Ihe 

 lypcs with ihe difïercnl conil)inalions oC genetic faclors prodnced by thc biolo- 

 gisl, must remain in tiie iiands oC llie pi'aclical mon, al the horlicullural or 

 agricull lirai experinienl-slalions. 



In those cases where llie new Ihing reqnired is a lypo wliich will ]><• cspe- 

 cially well adaplod lo adverse climalic conditions, \ve mnsi remcmher thaï if 

 we Iry to reach our goal by crossing wilh a résistent form, the firsl hybrid 

 génération need not necessarily be résistent, ^^'e can only hope to find onr 

 new type, amongsl the individuals ofthe second génération, and the larger \ve 

 can make the numbcr of Fjindividnals, the bélier is our chance of finding what 

 \\e want. It is decidedly a great mistake lo risk the life of the F, individuals 

 by exposing Iheni to those conditions for which we seek a résistent form. 



il is therefore recommended always to proteci Ihe F; plants as \\(>ll as pos- 

 sible, so as noi to tel lliem die from droughl or IVeeze lo dealli. Thiough 

 neglecting llius lo prolecl the \'\ iiidividnals. niurji good w nrk lias alrcadx liccn 

 losl. 



