li. II. CllMI'IdN. - llli;ilT AM) I.RKI' Il ANDI'DNESS IN CURKALS. 5'211 



The ij^enotics of lii^lil ami lell iiaiulcdness are peculiarly inleresling, since 

 lliese cliaraclers ol' s\ iiiiiicliv belong- lo a spécial categ'ory quilc iinlike Ihose of 

 coloiir, hairiness, slaliiro, slerilily, elc, wliicli hâve lieen chioflysliulied during' 

 llie last len years. Connieting results liave Ijeen oblained hy workers on diffé- 

 rent animais, and nu i-lcar analysis has yel been niadc of Ihe faclors involved 

 in Ihe proljlem. In llie case of cereals il can be definilely slaled Ihat riglil and 

 left handedness in Ihe fold of the firsl leaf are nol hereditary cliaraclers. 



An experimenl with « Kinver Chevalier » may be quoled in suppoi'L of lliis 

 statenient. Seeds from planis with LU first Icaves were sown, and yielded 

 l!t(i(l LH, I iOl RH seedlings; 0/0 LH = r)S.Ô2. The seeds from RIl parents gave 

 llill'.l LH, Mot) RH offspring: 0,0 LH =r:.8.l'.l. Olher experimenls gave siniilar 

 négative results. 



Though Ihe RH and LH cliaraclers Ihemselves are not inheriled, the i-alio 

 between Ihe nnmbers of LH and RH oITspring is constant in successive géné- 

 rations of the sanie stock, and thus seems to be an hereditary spécifie character : 

 Ihis has been observed in Ihrec générations of « Kinver Chevalier » Barley. 

 Mi)reover, like olher ([iiantitative characters, the ratio shews fluctualing varia- 

 liilily. In studying llic oll'spring of a large number of individual spikes of 

 » Plumage Corn » il was found that the percentages of LH seedlings, vvhen 

 plotled against their frequencies of occurrence, gave a simple curve of conti- 

 nuous variation, symmetrical about the average 00 0. 



The reason for the dcparture from equality of RH and LH seedlings 

 remains obscure. U may be noted that similar discrepancies hâve been 

 recorded in Ihe cases of (I) the optic chiasma ofTeleostei(Larrabee),where oui 

 of iOlu brooktrout àO 0/0 were RH, but no inheritance was observed, and (2i Ihe 

 mode of hand-clasping in nian (F.-E. Lutzl, where almost exactly 00 0/0 place 

 the right thumb uppermost, and when^ a certain degree of inheritance occurs 

 (as in other cases of human asymmetry). 



In Oats (Avcna .-irt//r«) we llnd the inverse resuit of that givcn by Rarley. a 

 considérable excess of RH. seedlings being présent in a randoni collection. A 

 sample of " Thousand Dollar " Oats yielded iOl) LH., 570 l\U. seedlings; 

 (I LH. := ii,H8. This inversion ruiis parallel with another asymmetry pheno- 

 nienon. In Rarley the nature leaf-blades ai-e loosely rolled into a RH. spiral : 

 in Oats the spiral is LH. This twist is the saine whatever the mode of lolding 

 of Ihe leaves, and is somelimes used as a diagnostic character. Il is diflicuil 

 lolind a reason for the paralleiism between it and thepercentage of l!ll. and LH. 

 seedlings in respect of the fold of the first leaf. 



Six-Rowed Barley llnr<lcuiii he.r(:t>ilkht(iri an<l Setaria ilalica also gave an 

 excess of LH. seedlings. 



In Maize (Zca .l/rti/.'i) weareconfronted with dilïerenl phenomena. The seeds 

 are arranged on the « coli » or inflorescence in a variable number of pairs of 

 vertical rows : the members of each pair may be distinguished as « odd » and 

 « even » according to the following convention. Taking a 9 round-plan of Ihc 

 cob, and passing round it in the direction of the hands of a clock, the first 

 member of each pair of rows to lie encountered is called. « even » the second 

 . odd ». 



We saw that in Barley there is no relation between the position of the seed 

 on Ihe spike and Ihe fold of the first leaf. In Maize, however, there is a clear 

 connection. Generally speaking, odd rows give an excess of RH. seedlings, 



