STUDIKS ON Tin: (iEXKTICS dl' FlyiWER-CllLOUliS, ETC. 



129 



in jP, (35 and 12 mngentas pixxlucctl respot^tixoly). The orange and llie rwl 

 fdiuul ill ii^l(liti(;n li;ivo probably been pi-oducecl by the " loss-mutatiou", but 

 as to the male of production of fli'sh-colouretl phiuts we ai-e in the same 

 position as iu respect to Nos. 17 and 18 just cited, and consequently we are 

 not able to make any simuise about it. 



\. Ckanyc of the IdnJaiyc Ratio. In No. 24 we see tluit one mageuta 

 ex wliite-n x magenta segregate? into 28 magentas, 2 reds, 3 oranges and 11 

 ■whites. We may consider this niiigenta parent to have had the composition 

 CcJirJih, and the appeai'ance of 2 reds which luive never been met with in 

 Jf^-geueration (with one exception, s. the Table VI, A) is, as I think, due tf) 

 the change of the complete hukage between JB and B into a paiiial, as we 

 have seen in the Ci'oss VHI. Suppose tluit jB and B are Huked according 

 to the series 7i : 1 : 1 : « ; since no such relation exists betvveeu C and li or 

 between C and B, we should lojive the eight ibllowing classes of gametes iu 

 the ratios indicated, ^'iz..• — 



nCJRB + ncBB + lCrB+ IcvB^lCRh + IcRb ^nCrh^-ncrb. 



The mating of male and female gametes of such constitutions should give rise 

 to the four following kinds of zygotes iu the ratios indicated, viz.: — 



Though the number of individuals iu No. 24 is rather small, the following 

 calculations were made. Since we have observed in the Cross VIII the 

 linkfige between R and B belonging to the series 5:1:1:5 or (> : 1 : 1 : 6, 

 I have put ?^=5 or 6, and theu we have iu respect to the expected number 

 of individuals for each kind of zygotes. 



