779 



Th-j Jcurnal of Heredity 



111 view ot the almost perfect inter- 

 gradation of tyi)es as already exjjlained 

 and. Ix-nce, the dit^culty of making 

 exact numerical separations, tlie data 

 actually f»nuid and the theoretical ex- 

 pectatioJis show a rather remarkahle 

 closeness of lit. Especially note- 

 worthy is the fact that all of the theo- 

 retically expected groups are present. 

 and in no case hehave in a manner con- 

 tradictory to the assumed factorial 

 exj)lanation. 



Manv stutleiits of grain texture in 

 wheat have heen confused and misled 

 hv the occurrence of so-called "yellow 

 herrv" in hard wheats. Many wheats 

 which in a northern or dry climate ])ro- 

 duce hard, translucent grains, in a more 

 himiid or southern climate will produce 

 a greater or less ])roportion of grains 

 containing opa(|ue spots in the endo- 

 sperm. ( Irains containing such spots 

 are commonly called "yellow berries." 

 W lull the oinique spot is extended to 

 include all or nearly all of the t iido- 

 siK-rm. the whole grain appears to he 

 oiKique " and may be easily mistaken 

 for an ordinary soft wheat. The dif- 

 ference, however, is, in most cases. 

 easily determined by a microscoi)ic ex- 

 amination (jf thin Ncctions pre])ared as 

 •described above. I'ig. 16 gi\es >e\- 

 eral types showing llu- intergrading 

 series from a true hard to a trnv soft 

 wheat, indicating that grain lextuii- is 



Table VI. — Environir ]'(iri(itioiis in Pcrdula^c 

 Hard 



Pedigree Xo. Environic crmdilion 



a ([uantitative character depending, in 

 all i)robal)ility. upon the relative pro- 

 portions of starch and gluten in the 

 en(losi)enii as previously explained. 

 These were all from the see(ls of a 

 single hybrid wheat plant which was 

 heterozygous for grain texture. Fig. 

 17 gives a paralllel series from a single 

 plant of a ])ure raci' of a hard wheat 

 (Algerian macaroni), and exhibits sev- 

 eral t\pes extending from a grain which 

 was translucent tln-oughout, to those 

 with larger and larger "yellow berry" 

 spots until the endosperm (»f the seed 

 at the right is practically all included 

 in the yellow s])()t. V'\g. 18 gives a 

 similar series taken from an F., maca- 

 roni .Sonora hybrid ])lant which was 

 homozygous for bard grain texttire. 

 Comparing l'"ig. lf> with Fig's. 17 

 and 18 one readily sees that the air 

 spaces causing the o])a(|ueness of the 

 "N'ellow I'.erry .Spot" lie in flakes, 

 whereas those of tlu' true soft wheat 

 are dilVuse. 



i[i;Ki:i)rr\' ok "n i:i.i.ow i;i;km" 



The heredity of the diffuse or true 

 softness has been shown and disctissed 

 above. We mav now investigate the 

 nature and heredity of "N'ellow berry." 

 The following table gives a number of 

 selected cases showing the variation in 

 (be ])i'rcc'nlagi' ol \cllow liei"r\' m ',mve 

 biU'S of bard wluats in dilU-rent years 

 and wlieii grown under ditierr-nt en- 

 \ironic conditions in the same year: 



of " Yellow Berry" Grains in Pure Livrs of 

 Wheat 



Pcrccntaj?e of yellow berries in crop of 



lOU 



3(y-V) 

 36-20 

 .%-21 

 .^6-4.^ 



.^6- .SI 

 36- .SI 

 36-81 

 36-81 



3- 1 2 



Nursery row Yuma 3,S 



Nursery row Yuma 97 



Nursery row Yuma 31 



Nursery row Yuma 36 



Inerea.se plot Yuma 



.Nursery row Yuma l.S 



Increase plot Yiim.i 



Nursery row Yuma 1 1 



Increase ]>](>{ Yuma 



.Nursery row Yuma II 



i<n,s 



10 

 .S4 

 43 

 .SO 

 0,S 

 2H 

 <)6 

 33 

 K.S 

 <>6 



1016 



3.S 

 



42 

 4 



3.S 



12 



Where the pt'rccntage of yellow lire endosperm. < )n the oilier band. 

 berries was large, the <»])a(|ue spots were where the ])ercentage of yellow berries 

 large and fre(|uently included the en- was small, the opacjue spots were !.":iall 



