S. v. IIahlam) \{)\) 



Thum* iX'.Hiill^ slnui^I}' MU^^i'Ht that thr 4/) : M : I *> : I niti(» <l«Mh ikhmit. 



In ri'^inl to th«' Ix^havioiir nf tin* \Vatji«»nH it is clmr that wh<*th<T 

 t»iio or two Holsti'in factors arr cnnciriu*!. l\v<» WjitMnn.s nut of thn*** 

 wouKi Ix- iuonohy)tri() himI the thii^l \voul«l hn^Ml trin'. 10 liiinilicH wm* 

 ^»\vii fn»in F, Watsons. All prnvoH t«» Ix* iimnuhyhrnl. The al)H4ii<M- 

 of the |Hin' ty|H' sr^ins to lUM'd liirtlui inv«'sti^ali<in. Small .m- ImIi.ivcs 

 in /', a(x*onliiik( to I'xjKrtation ami l>rr«Mis trur. 



A lurthrr |H»iut imw iummIs «li.s(Missi(>n. ( )m the \\\<* H tarim Ii\|k.- 

 thosis thr nitio nf H Lo h in F. slmuM hr !,*) : I, .ind ihr rat in iH-twcrn 

 N, W, If. and .S'/s sh.Mild hr 45 : .S : 1.') : I. This is not totind U* \h- ih*- 

 wuH'. Thr nitio n\ 49 : l() in F, of H to h is far fnun <'X|KCtatinn, an<l 

 tiMusion has already hwu niadr t»» the ahiKunial lalius foinxl in the 

 het<.M\)zvi,^»iis fannlios of th<' /',. If the t\v(» H factor hyi>oth«sis is 

 corn.'ct how can tho diviation from the 15: I ratio he accounted fnr !* 

 Two possible explanations sugi^est themselves. 



{(t) The Solid parent may have been heterozygous tor on*- <»i ihc 

 two H fact<»rs, and in that wise some of th«' F.^. familit-s would show the 

 9 : .S : 8 : 1 ratio and others the 45 : *3 : 15 : 1 ratio. The numbers ol)- 

 tiuneii in the F.2 families are too small for any discussion of this p(»int 

 to have much value. As they stand, however, they do not lend any 

 support to this theory. 



(6) The ratio of 4*9// to III in F.^ may be accounted for by assuming 

 linkage between the two H factors. The /^., results could not be ;ie- 

 counted for by such an assumption. No hypothesis can at present be 

 suggested which will explain in all the results. The (piestion is evi- 

 <lently a conipliciited one, and the whole experiment is being lepeated 

 in the ho^x* of elucidating the various points that have arisen. 



The unexpected results which were obtained in Cross 1 in respect 

 of the inheritance of pattern on the seed coat led to the study of two 

 other crosses between Solid and Small eye, viz. Cross 2, Red Solid ])y 

 Black eye, and Cross 5, Red Solid by Brown eye. The results of these 

 two crosses will now be set forth and discussed. 



(•ros.s2. Red Solid by l^''^'^'^ ^y"- 

 *^ (Small eye. 



The F, was Solid. In the F. segregation occurred into Solid, 

 Watson, Holslein Saddle (types e and /' of Spillman). Holsttin Large 

 eye s}K)tt<'ci, and Small eyt*. All the Holsteins weic classified t(»gether. 

 From the numeriwil n-sults, which are presented in Table X, it will be 

 seen that the ratio of ir to ir is close to :i — 1 while the ratio of // to // 



